Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Imperial Jasper
A prized Mexican jasper known for pastel green, lavender, and cream orbicular patterns that take an exceptional polish.
mineralElephant Skin Jasper
A gray-brown jasper whose mottled, wrinkled patterning resembles elephant hide, also sold as Miriam or calligraphy stone.
mineral
Bruneau Jasper
A prized Idaho picture jasper from Bruneau Canyon known for brown and cream orbicular egg-rock patterns and scenic landscapes.
mineralSpiderweb Jasper
A jasper crossed by fine dark veins forming a spiderweb-like network, often a brecciated stone cemented by darker matrix.
mineral
Covellite
A soft copper sulfide famous for its intense indigo-blue color and dazzling iridescent metallic sheen, prized by collectors.
mineral
Mustard Jasper
A warm mustard-to-ochre yellow jasper colored by iron, valued by lapidaries for its rich, earthy golden tone.
gemstoneFancy Jasper
A soft-toned, multicolored jasper with swirling green, mauve, and cream patterns, popular and affordable in the bead trade.
sedimentary
Picture Jasper
An opaque brown chalcedony whose iron-stained banding mimics deserts, dunes, and distant mountain skylines.
mineral
Andesite
A fine-grained, intermediate volcanic rock common at subduction-zone volcanoes, between basalt and rhyolite in composition.
igneousAppinite
A group of coarse, water-rich plutonic rocks dominated by large hornblende crystals set in feldspar, intermediate between lamprophyre and diorite.
igneous
Unakite
An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.
metamorphic
Greywacke
A hard, dark, poorly sorted sandstone with a muddy matrix, typically deposited by underwater turbidity currents.
sedimentary
Basalt
A fine-grained, dark volcanic rock that erupts as fluid lava and forms most of the ocean floor and many lava plateaus.
igneousRainforest Jasper
An Australian green rhyolite with eye-like orbs and earthy patterns marketed as jasper, evoking dense rainforest foliage.
igneousGold Sheen Obsidian
A black obsidian displaying a golden metallic sheen caused by light reflecting off aligned microscopic gas bubbles or mineral inclusions.
igneous
Bixbite
An old trade name for red beryl, the extremely rare manganese-colored beryl from Utah, now largely replaced by the term red beryl.
gemstoneMaligano Jasper
A rare Indonesian jasper from Sulawesi known for ghostly tube structures, brecciated patterns, and contrasting grey, red, and purple zones.
mineral
Phyllite
A fine-grained foliated metamorphic rock between slate and schist, recognized by its silky silvery sheen and wavy, crinkled surfaces.
metamorphic
Green Moonstone
A pale green variety of feldspar moonstone showing a soft white or bluish adularescent sheen over a greenish body.
gemstone
Bloodstone Jasper
A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.
mineralPaintbrush Jasper
A scenic jasper whose flowing streaks of warm color resemble strokes left by a loaded paintbrush.
mineral
Chromite
Chromite is the only commercial ore of chromium, a black iron-chromium oxide of the spinel group found in mafic igneous rocks.
mineral
Nevada Opal
Opal mined in Nevada, famous for fiery black precious opal and opalized wood from the Virgin Valley district.
gemstone
Boulder Opal
Precious opal that forms in thin veins within brown ironstone boulders, cut with the host rock left as a natural dark backing.
gemstone