Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Apophyllite
A glassy, often colorless silicate that forms pyramid-tipped cubes and is famed for its pearly basal cleavage and watery clarity.
crystal
Green Quartz
A green variety of macrocrystalline quartz, usually the heat- or radiation-altered prasiolite, prized for its soft mint hue.
crystal
Green Aventurine
A green quartz speckled with shimmering fuchsite mica that produces a glittering aventurescence, popular as an affordable ornamental stone.
mineral
Lemon Quartz
A vivid greenish-yellow quartz, usually heat-treated or irradiated, prized for its clean clarity and bright lemon color.
crystal
Green Jasper
An opaque green variety of chalcedony quartz colored by iron and chlorite-group inclusions, prized as a durable carving and cabochon stone.
mineral
Gary Green Jasper
An Oregon jasper, also called larsonite, of silicified fossil wood showing olive-green fields laced with black dendritic patterns.
mineral
Emerald in Matrix
Natural emerald crystals still embedded in their host rock, prized as mineral specimens that show how the gem grew in place.
gemstone
Prase
An old name for a dull leek-green variety of quartz or chalcedony colored by green mineral inclusions, historically called mother of emerald.
crystal
Prasiolite
A pale green variety of quartz, usually created by heat-treating amethyst, often marketed as green amethyst.
gemstone
Amegreen
A natural bicolor quartz blending amethyst purple with prasiolite green in a single crystal, prized as a metaphysical heart-crown stone.
crystal
Aventurine
A translucent quartz speckled with glittery mineral inclusions that produce a shimmering aventurescence, most often green.
crystal
Mariposite
A green, gold-associated metamorphic rock made of chrome-rich mica and quartz, named for Mariposa County in California's gold country.
metamorphic
Epidosite
A hard, pistachio-green rock composed mainly of epidote and quartz, formed by hydrothermal alteration of mafic rocks.
metamorphic
Onyx
A banded variety of chalcedony quartz, classically black or black-and-white, long favored for cameos and beads.
gemstone
Black Onyx
A solid jet-black chalcedony, usually a dyed and treated agate, prized for sleek polished beads, cabochons, and intaglios.
gemstone
Unakite Jasper
An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.
metamorphic
Chrysoprase
A translucent apple-green chalcedony colored by nickel, the most prized green variety of the quartz family.
gemstone
Prehnite
A translucent yellow-green silicate famous for its botryoidal 'grape' clusters, often hosting needle-like sprays of black epidote.
mineral
Unakite
An altered granite mottled pink and green from feldspar and epidote, popular as a tough, colorful ornamental rock.
metamorphic
Flower Jasper
A jasper whose radiating mineral clusters form flower-like rosettes scattered across an earthy background.
mineral
Bamboo Agate
An agate whose layered, segmented banding resembles the jointed stalks and leaves of bamboo.
gemstone
Frog Skin Jasper
A mottled green jasper whose blotchy spotting resembles frog skin, valued by lapidaries for its earthy, camouflage-like patterns.
gemstone
Rainforest Jasper
An Australian green rhyolite with eye-like orbs and earthy patterns marketed as jasper, evoking dense rainforest foliage.
igneous
Grape Agate
Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.
mineral