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Crystal & Stone Compendium | Mila’s Exotic Plants

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Luminary Oddities

The mineral atlas

Crystal & Stone Compendium

Explore 105 crystals, rocks and gem materials through their formation, identifying features, documented human uses and attributed spiritual traditions.

105 specimens · Geology, history, and spiritual attributes

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All specimens Quartz and optical varieties Chalcedony and jasper families Feldspars and green stone families Gem minerals Colorful mineral families Tumbles and collector minerals

105 specimens

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Dark stones and fossil materials

Rocks and extended assortment

Clear quartz illustrated with broad prism faces, pale internal veils and a tapered crystal point.

Rock Crystal

Clear Quartz

Quartz, crystalline silica (SiO2).

Clear quartz is the colorless variety of crystalline quartz, also known as rock crystal.

Read the specimen guide↗

Rose quartz illustrated as a pale pink, irregular block with overlapping angular surfaces, fine dark fracture lines and small dark patches along its edges.

Pink quartz for carving, jewelry and collecting

Rose Quartz

Pink massive quartz / silicon dioxide

Rose quartz is the familiar pink variety of quartz, usually encountered as cloudy masses rather than sharply pointed natural crystals.

Read the specimen guide↗

Amethyst illustrated as a cluster of violet points above pale crystal bases and a layered green-gray matrix.

Violet quartz, from crystal-lined cavities to carved and faceted gems

Amethyst

Purple quartz.

Amethyst is purple quartz.

Read the specimen guide↗

Citrine illustrated as closely packed golden-orange points, with pale crystal faces and a broad white base.

Yellow and orange quartz, with a color history worth knowing

Citrine

Yellow to orange quartz.

Citrine ranges from pale yellow to warm orange and brownish orange.

Read the specimen guide↗

Smoky quartz illustrated as a broad gray-brown fragment, with angular broken surfaces, cream-colored highlights and darker patches.

Gray and brown quartz shaped by crystal chemistry and irradiation

Smoky Quartz

Brown to near-black quartz.

Smoky quartz ranges from a faint gray-brown tint to a depth that looks nearly black.

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Ametrine illustrated as a rectangular faceted gem, with golden-yellow color on the left and violet on the right.

Purple and golden quartz within one crystal

Ametrine

Quartz combining amethyst-purple and citrine-yellow/orange zones.

Ametrine combines the purple of amethyst with the yellow or orange of citrine in a single quartz crystal.

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Included quartz illustrated as an angular brown-gold fragment, with fine golden needles crossing darker interior areas and pale fractured edges.

Mineral needles, growth outlines and trapped fluids within quartz

Included Quartz

Quartz containing other minerals or visible growth features.

Included quartz is a collecting category rather than a single mineral variety.

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Pale green aventurine illustrated as a broad, irregular fragment with layered green shading, scattered cream-colored flecks and fine dark fissures.

Quartz with Reflective Mineral Inclusions

Aventurine

Aventurescent quartz-rich material with reflective inclusions.

Aventurine is a quartz-rich material distinguished by small flashes from enclosed mineral flakes.

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Tiger's-eye illustrated as a golden rectangular slab with diagonal streaks, dark brown bands and an irregular dark zone crossing its center.

Chatoyant Quartz

Tiger’s Eye

Chatoyant quartz-rich material associated with fibrous amphibole textures.

Tiger's-eye is a quartz-rich ornamental stone whose golden-brown bands carry a moving, silky reflection.

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A rounded pietersite illustration with sweeping slate-blue and rust-brown areas, golden streaks and a pale highlight across its polished surface.

Chatoyant Silica with a Patchwork Texture

Pietersite

Trade material with chatoyant fibrous inclusions in microcrystalline quartz.

Pietersite is a silica-rich ornamental material whose blue-gray, gold and reddish-brown patches carry a shifting sheen.

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An angular agate illustration with ochre and cream bands surrounding a pale pink-white center, dark fissures and a rough brown lower edge.

Bands, Cavities and the Architecture of Silica

Agate

Patterned, commonly banded chalcedony, a fine-grained silica material.

Agate is a patterned variety of chalcedony, not a separate mineral species.

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A broad, irregular blue lace agate illustration with closely spaced blue-and-cream ribbons, dark crossing fissures and a narrow ochre outer rim.

Pale Banded Chalcedony from a Complex Vein System

Blue Lace Agate

Pale blue-and-white banded chalcedony.

Blue lace agate is recognized by pale blue and white bands that curve, branch and fold across a cut surface.

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A circular pendant illustration with dark green, moss-like branching across a creamy pale field, a denser blue-green area on the right and a silver-colored bail above.

Mineral Landscapes in Fine-Grained Silica

Moss and Tree Agate

Chalcedony with mineral inclusions resembling moss or branches.

Moss agate contains inclusions that resemble branching plants, tangled foliage or small landscapes.

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An oval, cream-colored cabochon illustration with small black branching clusters scattered across its center and denser fern-like markings around the edges.

Branching Mineral Patterns in Chalcedony

Dendritic Agate

Chalcedony with branching mineral inclusions.

Dendritic agate contains dark, branching inclusions that can resemble ferns, roots or distant trees.

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A broad, irregular stone illustration with burnt-orange margins, a cloudy gray-cream center and fine dark fractures crossing its face. A pale, rough outer edge contrasts with the warmer interior.

Warm-Colored Chalcedony, Carved and Worn Across Centuries

Carnelian

Orange to reddish chalcedony.

Carnelian is the orange to reddish-brown member of the chalcedony family.

Read the specimen guide↗

A broad, pale cream and gray stone illustration, crossed by fine fractures and rusty branching marks. Small ochre patches interrupt its softly shaded, irregular face.

The Fine Structure Behind a Family of Gemstones

Chalcedony

Microcrystalline/fibrous silica aggregate; includes many named gem varieties.

Chalcedony connects stones that can look entirely unlike one another: pale blue cabochons, orange carnelian, banded agate and green chrysoprase.

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An irregular stone illustration with bright mint- and emerald-green patches separated by cream-gray matrix, dark crevices and small exposed cavities.

Nickel's Green Signature in Chalcedony

Chrysoprase

Nickel-colored green chalcedony.

Chrysoprase is green chalcedony whose color is associated with nickel-bearing material dispersed through its fine silica structure.

Read the specimen guide↗

A roughly triangular stone illustration with dark forest-green upper areas and broad brick-red patches across the lower face. Pale seams and fine fractures divide the contrasting colors.

Green Silica Marked by Iron-Red Inclusions

Bloodstone

Green chalcedony/jasper material with red markings.

Bloodstone, or heliotrope, is green chalcedony marked by red iron-oxide inclusions, commonly hematite.

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An oval, warm-brown gem illustration framed by pale gray and white layers. A helmeted figure stands within the brown center, holding a long spear and a shield; bright highlights emphasize the carved contours.

Layered Chalcedony for Seals, Cameos and Contrasting Color

Onyx and Sardonyx

Parallel-banded chalcedony; sardonyx includes sard-colored bands.

Onyx and sardonyx turn mineral layering into a design material.

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An irregular red-orange stone illustration crossed by fine dark fractures. Ochre margins, pale gray patches and scattered white highlights frame a broad, richly colored central surface.

Opaque Silica in Color, Pattern and Geological Context

Jasper

Opaque, impure, fine-grained silica-rich material; retail use of the name is broader.

Jasper is a broad name for opaque, fine-grained silica-rich material selected for its color and pattern.

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An irregular slab illustration with deep green fields, cream bands and pale pink margins. Small concentric circles crowd the center, while larger pale rounded forms occupy the left side; scattered brown openings interrupt the polished-looking surface.

Orbicular Chalcedony from Madagascar

Ocean Jasper

A lapidary trade name associated with orbicular silica-rich material from Madagascar.

Ocean Jasper is a trade name for patterned, silica-rich material from northwestern Madagascar.

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An angular stone illustration divided into deep red and golden-yellow fields by a curved pale boundary. Burgundy edges, fine fractures and cream highlights give the slab a layered, uneven appearance.

Western Australia's Radiolarian Stone in Red, Ochre and Cream

Mookaite

Silicified radiolarian sedimentary material from Western Australia.

Mookaite is a decorative rock from Western Australia, valued for broad fields of mustard yellow, cream, red and wine-purple.

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A cluster of aqua-green, blocky crystals illustrated with cream-colored streaks, stepped edges and a pale supporting matrix.

Blue-Green Microcline

Amazonite

Green to blue-green microcline feldspar.

Amazonite is the blue-green variety of microcline feldspar.

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Labradorite illustrated as a broad gray fragment with angular faces, deep blue patches and a rough brown edge.

Iridescent plagioclase feldspar

Labradorite

A plagioclase feldspar variety known for labradorescence.

Labradorite is a feldspar best known for broad flashes of blue, green, gold and other colors that appear as the stone turns in the light.

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Pale gray-white feldspar illustrated with stepped surfaces, soft blue highlights, crossing fractures and scattered dark accents.

Feldspar with Adularescence

Moonstone

Adularescent feldspar material, classically intergrown alkali feldspars.

Moonstone is admired for a moving sheen that seems to float within or just above its surface.

Read the specimen guide↗

A rounded peach-colored stone illustrated with copper-orange patches, fine bright sparkles, pale clouding and a few dark accents.

Feldspar with Reflective Inclusions

Sunstone

Feldspar gem material with reflective inclusions, sometimes showing aventurescence.

Sunstone ranges from softly sparkling peach-colored material to transparent red, green and multicolored gems.

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A blocklike gray stone illustrated with a coarse mosaic of pale and dark grains and scattered patches of blue light.

Norway's Blue-Flashing Ornamental Rock

Larvikite

Norwegian igneous rock rich in feldspar that can show blue-silver iridescence.

Larvikite is a coarse-grained igneous rock whose gray feldspars can flare blue or silver when the light catches them.

Read the specimen guide↗

A cluster of glossy black prisms with deep lengthwise grooves, angular terminations, silver-gray highlights and warm brown surface accents.

A Mineral Family in Many Colors

Tourmaline

Borosilicate mineral supergroup / black tourmaline focus

Tourmaline encompasses a family of boron-bearing silicate minerals rather than a single composition.

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An irregular green stone illustrated with pale granular mottling, dark branching fractures and ocher accents along the broken surfaces.

Interlocking Minerals, Enduring Craft

Jade

Jadeite jade and nephrite / a material umbrella

Jade is valued not only for color but for the dense mineral fabric that allows it to become a fine-edged carving, a smoothly rounded bangle or a luminous cabochon.

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A roughly rectangular green stone illustrated with olive and deep-green patches, cream diagonal veins and branching dark seams.

Green Minerals Formed Through Transformation

Serpentine

Serpentine-group minerals and serpentine-rich rock

Serpentine is a group of hydrous magnesium silicate minerals; serpentinite is a rock composed largely of them.

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A deep burgundy crystal illustrated with broad polygonal faces, nearly black shadows and scattered pale surface accents.

A Shared Structure, a Remarkable Palette

Garnet

A group of related silicate minerals.

Garnet is a mineral family, not a synonym for dark red.

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A luminous yellow-green fragment illustrated with broad olive planes, fine vertical strokes, branching dark fractures and warm ocher accents near its lower edge.

Green from the Earth's Interior

Peridot

Gem-quality olivine, usually magnesium-rich.

Peridot is the transparent, gem-quality form of olivine, a magnesium–iron silicate.

Read the specimen guide↗

An upright pale aqua prism illustrated with broad vertical faces, a broken-looking upper surface, fine dark fractures and cloudlike white highlights.

The Sea-Blue Variety of Beryl

Aquamarine

Blue to blue-green beryl.

Aquamarine ranges from delicate greenish blue to a more concentrated blue.

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A vivid green, flat-topped prism rises from a rugged cream and brown matrix, with dark outlines and mottled highlights emphasizing the contrast between crystal and surrounding rock.

Green Beryl, Revealed Within

Emerald

Green beryl in the gemological emerald range.

Emerald is the green to bluish-green variety of beryl.

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A broad pale pink-gray crystal illustrated with angular faces, smoky internal patches, fine fractures and an irregular cream-colored lower edge.

Pink Beryl, from Crystal to Jewel

Morganite

Pink to orange-pink beryl.

Morganite is beryl in shades of pink, rose, peach and pale violet.

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Cream-white prismatic crystals rise from a tawny base. Flat ends, gray patches and finely drawn edges emphasize the cluster's architecture rather than the transparency of a polished gemstone.

Goshenite, heliodor and the mineral behind a spectrum of gems

Other Beryl Varieties

Beryl family material outside the dedicated aquamarine, emerald and morganite pages.

Beryl is the mineral species; emerald, aquamarine, morganite, heliodor and goshenite are names used for particular appearances within it.

Read the specimen guide↗

A pale rose fragment spreads horizontally into layered projections. Fine gray fractures and white highlights trace its broad surfaces, while open slots give the left edge a delicate, branching silhouette.

Pink and green spodumene, with color that deserves a precise name

Kunzite and Hiddenite

Colored varieties of spodumene.

Spodumene is a monoclinic pyroxene, commonly forming flattened, elongated crystals with lengthwise striations.

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Deep blue blades cross a cream-colored matrix in long, angular strokes. Pale streaks follow their length, while dark outlines distinguish broken edges, overlapping crystals and the rough rock beneath them.

Blue blades that reveal the importance of direction

Kyanite

Aluminium silicate mineral, polymorphous with andalusite and sillimanite.

Kyanite is triclinic and frequently grows as flattened blades, sometimes bent or intergrown.

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Muted indigo patches interrupt a coarse mosaic of cream and gray grains. The irregular outline and ocher lower edge present cordierite as part of a rock, rather than as a transparent, faceted jewel.

Violet-blue cordierite and the art of changing perspective

Iolite

Gem-quality cordierite, often violet-blue and strongly pleochroic.

Iolite is gem-quality cordierite, an orthorhombic mineral that often occurs as granular or compact masses rather than conspicuous free-standing crystals.

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A diamond-shaped section in dusty rose and warm beige carries four dark arms around an irregular ochre center. Pale seams interrupt the surface, giving the painted cross the uneven character of an inclusion pattern rather than a printed emblem.

Color in three directions; a cross within the crystal

Andalusite and Chiastolite

Andalusite; chiastolite is the cross-patterned inclusion variety.

Andalusite shares the composition Al2SiO5 with kyanite and sillimanite, but their atoms occupy different structures.

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Cream and ochre rock encloses a deep opening filled with rounded, pale sage-green growths. The broad broken rim and dark recess make the delicate interior the focus of the illustration.

Pale green growth within the spaces of older rock

Prehnite

Calcium aluminium silicate, often pale green and botryoidal.

Prehnite is a distinct mineral, not a pale kind of jade or quartz.

Read the specimen guide↗

Slender olive-black prisms spread in a dense fan, their long ridges picked out by yellow-green highlights. A broad upright crystal rises at the upper left; pale angular forms brighten the opposite edge.

Dark prisms, green interiors and the evidence of alteration

Epidote

Calcium aluminium iron silicate in the epidote group.

Epidote contains calcium, aluminum, ferric iron, silicon, oxygen and hydroxyl.

Read the specimen guide↗

An elongated green rock is painted with dark flecks, branching seams and small muted rose-red patches. Its opaque, mottled surface represents ruby-bearing zoisite rather than a transparent blue tanzanite crystal.

One mineral species, several distinctive expressions

Zoisite and Tanzanite

Zoisite mineral; tanzanite is blue-violet gem zoisite.

Zoisite is an orthorhombic calcium–aluminum silicate containing hydroxyl.

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A long, barrel-like blue crystal lies horizontally, crossed by pale bands and fine dark fractures. Slate-blue faces, deep navy patches and ochre weathering give the illustration the character of rough sapphire rather than a polished jewel.

Corundum's colors, histories and hidden distinctions

Ruby and Sapphire

Red and other colored gem varieties of corundum.

Corundum is aluminum oxide.

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A pale, glassy crystal rests horizontally, its broad faces interrupted by cloudy seams, dark internal planes and an irregular broken end. The restrained grey-and-white palette draws attention to the geometry of the crystal rather than a gemstone's polished colour.

More than a familiar blue

Topaz

Aluminium fluorine/hydroxyl silicate mineral.

Topaz is an aluminium silicate containing fluorine and hydroxyl.

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Overlapping blue-grey cubes form a stepped cluster, with lilac patches near the upper edge and bright, broken planes below. Dark outlines emphasize the interlocking geometry while pale washes suggest translucent surfaces.

Color with an architectural edge

Fluorite

Calcium fluoride (CaF2).

Fluorite is calcium fluoride, a halide rather than a silicate.

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Honey-coloured, slant-sided crystals overlap across a charcoal-grey matrix. Cream highlights pick out broad faces and thin internal lines, giving the cluster a luminous, angular rhythm.

The mineral that makes a double image

Calcite

Calcium carbonate (CaCO3).

Calcite is calcium carbonate with a trigonal structure.

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A rust-orange cluster rises into a broad central peak, crowded with short prisms and pale polygonal ends. Cream highlights and dark recesses make the tightly packed forms appear to radiate in several directions.

The carbonate that builds in another way

Aragonite

A calcium-carbonate polymorph distinct from calcite.

Aragonite and calcite have the same chemical formula but different atomic arrangements.

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A broad orange-brown cap rests above a thick white band of closely aligned fibres. Fine grey shadows and cream streaks emphasize the vertical texture, while a few darker seams interrupt the pale surface.

Clear plates, silken fibers and carved stone

Gypsum: Selenite and Satin Spar

Hydrated calcium sulfate (CaSO4·2H2O).

Gypsum contains water as part of its crystal structure: the formula includes two water molecules for each calcium sulfate unit.

Read the specimen guide↗

A rounded blue-grey stone carries scattered cream flecks and a broad pale reflection across its left side. Deeper blue shading along the right edge gives the smooth form a quiet sense of weight.

A blue stone with two histories

Angelite

Trade name for blue-grey massive anhydrite.

Angelite is blue anhydrite rather than a separate mineral species.

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Pale blue-grey crystals cross and overlap in a dense cluster. Cream-coloured crusts cover portions of their broad faces and edges, while cool shadows separate the angular forms.

A chamber of pale blue light

Celestine

Strontium sulfate (SrSO4).

Celestine is orthorhombic strontium sulfate, SrSO₄, in the barite group.

Read the specimen guide↗

Cream and honey-coloured blades gather into two broad intergrown fans. Pale highlights run along their flat faces, with ochre shadows emphasizing the deep spaces between overlapping plates.

Delicate forms with unexpected weight

Barite / Baryte

Barium sulfate (BaSO4).

Barite is barium sulfate, BaSO₄.

Read the specimen guide↗

A dark blue-green prism lies diagonally across the composition. Fine cream lines traverse its long faces, while pale, irregular patches gather around the blunt ends and emphasize the contrast with the deeper interior colour.

A familiar name for a varied mineral family

Apatite

A mineral-group name; much gem material is fluorapatite.

Apatite is a group name rather than one colour or one fixed composition.

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Malachite illustrated as an irregular green mass with rounded ridges, dark cavities and exposed ocher-colored areas.

Green Copper Carbonate

Malachite

Copper carbonate hydroxide.

Malachite is a copper mineral whose green color is part of its chemistry, not an occasional variation.

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Azurite illustrated as deep-blue rounded growths among pale-green patches and ocher-brown rock.

Blue Copper Carbonate

Azurite

Blue copper carbonate hydroxide.

Azurite ranges from a pale powder-blue crust to intensely blue crystals that can seem almost black until their faces catch the light.

Read the specimen guide↗

Chrysocolla illustrated with teal crusts and rounded nodules across an uneven dark-brown base.

Blue-Green Copper Silicate

Chrysocolla

Copper-bearing hydrated silicate material, often intermixed with other minerals.

Chrysocolla brings blue and green to weathered copper deposits, as coatings, crusts or material enclosed in harder silica.

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Turquoise illustrated as pale-blue areas with cream-colored seams in a fractured ocher-brown rock.

Blue-Green Copper–Aluminum Phosphate

Turquoise

Hydrated copper aluminium phosphate.

Turquoise is an opaque to semitranslucent gem whose appeal lies in color, texture and the pattern of its surrounding rock.

Read the specimen guide↗

Sodalite illustrated as a broad blue rough mass with cream-colored patches, pale veins and brown seams.

Blue Feldspathoid and Light-Responsive Varieties

Sodalite

A blue to variable-colored feldspathoid mineral.

Sodalite is familiar in blue, pale-veined ornamental rocks, but the mineral has other colors too.

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Lapis lazuli illustrated as an angular blue fragment with pale flecks, gold-toned patches and dark fracture lines.

A blue ornamental rock

Lapis Lazuli

A rock containing blue lazurite with variable calcite, pyrite and other minerals.

Lapis lazuli is an opaque blue rock used for jewelry, carving, inlay and pigment.

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A rounded, triangular white stone is illustrated with a smooth surface and branching gray veining.

White borate, branching veining, and a modern association with patience

Howlite

Calcium borosilicate hydroxide, commonly white with dark veining.

Howlite is a white calcium borosilicate hydroxide, often crossed by gray markings.

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A pale cream, angular mineral block is illustrated with a broad upper face, fine surface fractures, and layered-looking edges.

Magnesium carbonate, from pale ornamental stone to an industrial mineral

Magnesite

Magnesium carbonate (MgCO3).

Magnesite ranges from white nodules to well-formed crystals.

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Elongated pink crystals are illustrated across a pale, granular matrix, with dark patches accenting the cluster.

Rose-colored manganese silicate, with a complex mineral story behind the pink

Rhodonite

Manganese-rich silicate material, often pink with dark manganese oxides.

Rhodonite appears in pink-and-black aggregates and transparent red crystals.

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Salmon-pink, blocky crystals are illustrated above a dark base, with fine pale points filling spaces around them.

Manganese carbonate in rose-colored bands and exceptional red crystals

Rhodochrosite

Manganese carbonate (MnCO3).

Rhodochrosite ranges from pink-and-white banded aggregates to transparent red crystals.

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Overlapping lavender-gray plates are illustrated against a pale, irregular host, emphasizing the layered texture and fine reflective edges.

Lithium-rich mica, layered sparkle, and the importance of a precise name

Lepidolite

Field/trade name for lithium-rich micas, not one accepted mineral species.

Lepidolite is the familiar name for lithium-rich mica material often seen in lilac or pink, with a sheen produced by many thin plates.

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A long, pale green-gray mineral mass is illustrated with overlapping, rippled layers, silvery edges, and a cream-colored margin. The emphasis is on the stone's folded, flaky texture rather than a polished surface.

Chromium-green mica, layered light, and the different stones hidden behind one name

Fuchsite

Chromium-bearing green muscovite variety.

Fuchsite is chromium-colored green muscovite.

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An angular violet-gray stone is illustrated with a compact, uneven surface, pale cream flecks, and fine darker fractures. Its muted mass contrasts with the transparent, needle-filled quartz sometimes associated with dumortierite.

Blue mineral fibers, quartz landscapes, and a history beyond ornamental stone

Dumortierite

Aluminium borosilicate, commonly encountered in quartz-rich material.

Dumortierite is an aluminum borosilicate occurring in fibrous masses and as needles within quartz.

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An upright violet-pink stone is illustrated with sweeping fibrous bands, pale seams, and a gray-white edge. The straight lower edge and swirling interior emphasize the contrast between a cut outline and the mineral's flowing texture.

Violet mineral fibers and a remarkable Siberian rock

Charoite

Complex silicate mineral usually sold as purple charoite-bearing rock.

Charoite's appeal is not simply that it is purple.

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A long, angular dark gray-brown rock is illustrated with pale seams and a small vivid pink-purple patch near one end. The composition emphasizes the colored mineral within a contrasting host rather than presenting the whole specimen as uniformly purple.

Purple silicate, mixed mineral textures, and the importance of genuine identity

Sugilite

A complex potassium-sodium lithium silicate mineral, often sold in mixed massive material.

Sugilite includes brownish-yellow material from Japan and the purple manganese-bearing South African material familiar in jewelry.

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A deep blue, irregular mineral mass is illustrated with rounded ridges, lighter blue margins, and a fine textured surface. Small pale flecks and a greenish-white base contrast with its darker recessed center.

Deep blue copper silicate, delicate fibers, and quartz that preserves a growth history

Shattuckite

A copper silicate hydroxide mineral, often present in blue-green mixed rocks.

Shattuckite brings an intense blue to the oxidized zones of copper deposits.

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A dense group of emerald and blue-green crystals is illustrated on an irregular cream-colored base. Contrasting facets, dark recesses, and scattered pale highlights give the cluster depth.

Vivid copper-green crystals with an intricate structure and vulnerable edges

Dioptase

Hydrated copper silicate, often emerald green.

Dioptase's vivid green invites comparison with emerald, but it is hydrated copper silicate, not beryl.

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White, fan-shaped crystal sprays are illustrated across an elongated rusty orange-brown matrix. Dark cavities separate the pale blades and emphasize their radiating arrangement.

Unlike crystal ends, zinc-rich origins, and a surprisingly varied appearance

Hemimorphite

Hydrated zinc silicate.

Hemimorphite forms pale crystal fans and rounded blue crusts.

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Rounded dark brown lobes are illustrated above a sharply broken, dark fibrous-looking edge. Red-orange seams and scattered pale reflections trace the boundaries between the raised surfaces.

The red mineral beneath a metallic surface

Hematite

Iron oxide (Fe2O3).

Hematite can be a polished dark mirror, a cluster of steel-gray plates, a rounded brown mass, or a fine red earth.

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A broad, irregular dark gray-black mass is illustrated with a rough face, branching fractures, and scattered pale patches. Subtle tonal changes describe the surface without implying polished crystal faces.

Iron oxide, natural magnetism, and the cultural life of lodestone

Magnetite

Magnetic iron oxide, distinct from hematite.

Magnetite is a black iron oxide whose magnetic response can be more striking than its appearance.

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Large brass-gold crystal faces are illustrated with parallel striations and sharp intersecting edges. Pale crystal clusters cross the center and right side, contrasting with darker recesses below.

Brass-colored geometry, reflective history, and a mineral that rewards careful storage

Pyrite

Iron sulfide (FeS2).

Pyrite's cubes can look manufactured, but their geometry belongs to natural crystal growth.

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An angular metallic fragment rendered in bronze and deep blue, with turquoise-green patches crossing its broken faces.

Iridescent copper minerals beneath a shared trade name

Peacock Ore: Bornite and Chalcopyrite

A retail label commonly applied to iridescent copper-iron sulfides.

Peacock ore is a name for an appearance, not a single mineral species.

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A black glassy fragment is illustrated with broad curved fracture surfaces, silver-gray highlights and a pale, rough outer margin.

Volcanic Glass, Sharp Edges and Reflective Depth

Obsidian

Natural volcanic glass, not a crystalline mineral.

Obsidian preserves a different outcome of cooling magma: glass rather than a framework of interlocking mineral grains.

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A flat charcoal-colored fragment crossed by pale gray and white veins, with angular edges and subtly reflective planes.

Ancient carbon-rich rock with a complex microscopic identity

Shungite

Name used for carbon-rich mineraloid and carbon-bearing rock from Karelia.

Shungite belongs to a family of dark, carbon-bearing rocks rather than to one simple, uniform crystal species.

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An elongated black-brown piece with a flattened face, subtle lengthwise markings and a gently tapered end.

Fossil wood transformed into a jewel of deep black

Jet

Organic gem material derived from fossil wood, not obsidian or anthracite by default.

Jet offers a different kind of beauty from a transparent crystal: a dense black surface that can be carved into delicate relief and polished until it reflects like still water.

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Amber illustrated as a broad, irregular fragment with honey-gold highlights, orange-red depths and dark lines crossing its glossy faces.

Fossil resin and a record of ancient forests

Amber

Fossilized resin, an organic gem rather than a crystalline mineral.

Amber is fossilized tree resin, valued for its warm color, light weight and ability to preserve traces of ancient life.

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An irregular cream-and-tan fragment with a dark brown center, lengthwise markings and scattered gray-black patches.

The architecture of a tree preserved in mineral form

Petrified Wood

Fossil wood preserved by mineral infilling/replacement, often silica.

Petrified wood retains the organization of something that once grew.

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An oval polished stone in warm gray and tan, patterned with pale honeycomb outlines, dark centers and fine radiating lines.

Ancient marine structures preserved in stone

Fossil Coral

Fossil coral material, sometimes replaced by silica.

Fossil coral brings the architecture of ancient animals into view.

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An angular gray-brown rock fragment is crossed by pale cream markings and fine cracks. The restrained illustration emphasizes its uneven surface and embedded fragments rather than presenting a reconstruction of the original organisms.

Ancient marine life preserved within carbonate rock

Fossil Limestone

Carbonate rock containing visible fossils.

Fossil limestone holds the remains of organisms within the stone that accumulated around them.

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A rounded gray section is crossed by gold and brown branching seams. The illustration draws attention to the irregular, star-like junctions between veins and the quieter areas of rock they enclose.

Mineral-filled fractures within a sedimentary concretion

Septarian Nodules

Concretions with internal cracks and later mineral fillings.

Septarian is a name for a patterned concretion, not a separate mineral species.

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A rough gray-brown fragment has an irregular outline and a surface crowded with cavities of different sizes. The illustration emphasizes the thin partitions between some openings and the heavier, solid areas between others.

Porous volcanic rock shaped by escaping gas and cooling melt

Lava Stone

Broad retail name, usually for vesicular volcanic rock.

“Lava stone” is a broad commercial description rather than a precise mineral name.

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An irregular rust-brown and amber stone is illustrated with curved fractured surfaces, pale granular seams and dark cavities; no rainbow play-of-color is depicted.

Hydrated Silica, Moving Color and Preserved Worlds

Opal

Hydrated silica material; precious opal shows play-of-color and common opal does not.

Opal can carry shifting spectral color, a quiet milky translucency or a rich brown body with no rainbow at all.

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An uneven olive-green glass fragment is illustrated with dark hollows, bright silvery ridges and a translucent-looking green margin.

Earthly Glass from an Extraordinary Impact

Moldavite and Tektites

Natural impact-generated glasses derived from terrestrial material.

Moldavite is associated with a collision from space, but its glass is transformed terrestrial material—not a green fragment of the incoming meteorite.

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An angular fragment displays pale green, coral-pink and gray-white areas separated by darker seams. The illustration emphasizes a rough mineral mosaic, with uneven edges and individual patches rather than a smooth, uniformly colored surface.

Pink feldspar and green epidote in an altered granitic rock

Unakite

Altered rock combining feldspar, epidote and commonly quartz.

Unakite's pink-and-green pattern belongs to a rock assembled from contrasting minerals.

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A polished oval has a cream-colored surface scattered with irregular black spots. A soft gray highlight follows its curved edge, emphasizing the smooth finish and the difference between the pale background and darker markings.

A pale feldspar-rich rock patterned with dark amphibole spots

Dalmatian Stone

Spotted ornamental rock; analyzed trade samples contain a feldspar-quartz matrix with arfvedsonite-rich dark areas.

Dalmatian stone is recognized by the contrast between its light groundmass and scattered dark spots.

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Kambaba stone illustrated as a rounded green piece with charcoal-black rings, irregular dark patches and fine pale seams.

Green Orbicular Volcanic Rock

Kambaba Stone

Green-and-black orbicular rhyolitic rock in the documented trade material.

Kambaba stone's dark rings and olive-green ground make it distinctive.

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Rhyolite illustrated as a pale salmon-pink angular fragment, with small dark flecks, scattered pores and irregular fractures.

Silica-Rich Volcanic Rock

Rhyolite and Patterned Volcanic Stones

Silica-rich volcanic rock, with varied textures and mineral mixtures.

Rhyolite is a volcanic rock whose composition is rich in silica.

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Gabbro illustrated as a broad angular fragment with an interlocking pattern of charcoal-gray, pale-gray and cream mineral grains.

A Coarse-Grained Igneous Rock

Gabbro / Indigo Gabbro

Gabbro is a coarse-grained mafic igneous rock; indigo gabbro is a trade label.

Gabbro is a dark, coarse-grained rock formed as mafic magma crystallizes below the surface.

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Bronzite-bearing material illustrated as a dark green-black angular fragment crossed by ochre seams and scattered pale reflective patches.

Bronzy Iron-Bearing Orthopyroxene

Bronzite

Bronzy-shimmering orthopyroxene material associated with the enstatite–ferrosilite series.

Bronzite names iron-bearing enstatite with a bronze-like reflection.

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Hypersthene-bearing rock illustrated with broad dark-gray grains, a pale cream network and ochre patches along irregular fractures.

A Legacy Name for Iron-Bearing Orthopyroxene

Hypersthene

Legacy name within the enstatite–ferrosilite series, retained in gem trade.

Hypersthene is a historical name for iron-bearing orthopyroxene, now classified within the enstatite–ferrosilite series.

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A polished nuummite cone illustrated in near-black and deep brown, with scattered gold-colored streaks and bright highlights along its curved surface.

An Amphibole Rock with Hidden Iridescence

Nuummite

Iridescent amphibole-bearing metamorphic rock associated with Nuuk, Greenland.

Nuummite is a dark ornamental rock whose polished surface can reveal narrow flashes of gold, bronze, blue or violet.

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Astrophyllite-bearing rock illustrated with elongated copper-brown blades crossing pale peach, cream and gray mineral grains.

Bronze Blades in Pale Stone

Astrophyllite

Titanium-bearing silicate mineral with often radiating golden-brown blades.

Astrophyllite is a titanium-bearing silicate best known for bronze and golden-brown blades that spread through a contrasting host rock.

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Arfvedsonite illustrated as a dark blue-black mass with long ridges, irregular fractures, green-gray margins and small patches of pale host rock.

A Dark Amphibole with a Complex Interior

Arfvedsonite

Sodium-rich amphibole mineral commonly in alkaline igneous rocks.

Arfvedsonite is a sodium-iron amphibole found in alkaline igneous rocks.

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Small pale apophyllite crystals illustrated within peach-lined cavities of a fractured gray host rock.

Clear Geometry in Mineral-Lined Cavities

Apophyllite

A group of hydrous silicate minerals.

Apophyllite names a group of hydrated silicates whose reflective, blocky or pointed crystals often line mineral cavities.

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Stilbite illustrated as overlapping peach-colored sheaves with pale, fan-shaped ends and finely ridged surfaces.

Open Frameworks, Fans and Fine Crystal Sprays

Zeolites: Stilbite and Scolecite

A family of hydrated aluminosilicates; species differ.

Zeolites are a family of minerals, not one stone with one formula.

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Cream-colored mineral patches and angular fractures cross a muted green-gray stone, with darker recesses emphasizing its irregular surface.

A Borosilicate of Clear Crystals and Quiet Color

Danburite

Calcium borosilicate mineral.

Danburite occupies an interesting space between mineral cabinet and jewelry case.

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A cluster of translucent-looking white and smoky-gray cubes rises from a rough brown-gray base, with bright square faces and smaller blocky crystals along the edges.

Salt Crystals, Vanished Waters and Preserved History

Halite

Sodium chloride mineral, occurring in evaporite deposits.

Halite is sodium chloride in mineral form.

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An illustrated slab combines turquoise fields, icy-white rounded patterns and fine pale boundaries within a rough, dark outer rim.

Blue Pectolite from the Dominican Republic

Larimar

Blue pectolite trade material from the Dominican Republic.

Larimar's blue-and-white pattern can resemble light moving over shallow water.

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Vivid red crystals punctuate a cream-colored matrix, including a sharply outlined octahedral form near the center.

A Gem with a History Beyond Ruby

Spinel

Magnesium aluminium oxide mineral.

Spinel does not need to borrow another gemstone's reputation.

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Brown prismatic crystals stand out from pale, layered rock, with a prominent asymmetric cross-shaped intersection at the center.

Natural Crosses in Metamorphic Rock

Staurolite / Fairy Crosses

Iron-rich aluminium silicate, sometimes naturally twinned into cross-like forms.

Staurolite's crossed crystals are among the most recognizable shapes in a mineral collection.

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Bright yellow patches interrupt a gray and olive-toned rough stone, with dark seams and fractures tracing its uneven surface.

Carbonate, Sulfide Pigments and Striking Bands

Bumblebee Stone

Carbonate-rich Indonesian decorative rock, despite the common jasper label.

Bumblebee stone takes its trade name from the contrast of yellow, orange, gray and black.

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A round faceted gem is illustrated in white and charcoal planes, with narrow rainbow flashes brightening the outer facets.

Silicon Carbide, Natural Rarity and a Grown Gem's Fire

Moissanite

Silicon carbide (SiC); rare natural mineral, with laboratory-created material supplying the gem trade.

Moissanite brings together two different stories: rare natural silicon carbide and deliberately grown crystals made into brilliant jewelry.

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