Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Tiger's Eye
A golden-brown chatoyant quartz with a shimmering silky band of light, formed when quartz replaces fibrous crocidolite.
gemstone
Lithic Sandstone
A sandstone in which the dominant grains are fragments of pre-existing rocks rather than single minerals, signaling rapid erosion nearby.
sedimentarySuper Seven
A trade name for quartz containing a combination of seven minerals including amethyst, smoky quartz, and cacoxenite, prized by collectors.
crystal
Dumortierite
A hard aluminum borosilicate famous for its rich denim-blue color, often forming dense fibrous masses or coloring quartz blue.
mineralFeather Jasper
A jasper marked with soft feather- or plume-like mineral inclusions that drift through a pale silica body.
mineralApricot Agate
A soft peachy-orange variety of banded chalcedony, naturally iron-tinted or dyed, popular for warm-toned beads and jewelry.
gemstone
Deschutes Jasper
A prized Oregon picture jasper from the Deschutes region known for soft scenic landscapes in cream, tan, and blue-gray.
mineral
Diorite
A coarse-grained intrusive rock with a distinctive salt-and-pepper look, the plutonic equivalent of andesite.
igneous
Black Agate
A deep black variety of banded chalcedony, often closely related to or treated like onyx, used for jewelry and carvings.
gemstone
Red Jasper
An opaque, iron-rich variety of microcrystalline quartz known for its deep brick-red color and ancient history as a stone of strength and grounding.
gemstone
Carnelian
A warm orange-to-red variety of chalcedony quartz colored by iron oxide, used since antiquity for seals, beads, and cabochons.
gemstone
Ametrine
A natural bicolor quartz that combines purple amethyst and golden citrine in a single crystal.
crystalRoyal Imperial Jasper
A premium Mexican imperial jasper showing soft pastel swirls and orbicular eyes in lavender, mint, cream, and rust.
mineral
Shattuckite
A rare deep-blue copper silicate mineral, often fibrous or massive, named for the Shattuck Mine in Arizona and prized by collectors.
mineral
Gabbro
A coarse-grained, dark mafic intrusive rock that is the plutonic equivalent of basalt, rich in plagioclase and pyroxene.
igneousNordmarkite
A light-colored alkali quartz syenite dominated by perthitic feldspar with minor quartz, from the Oslo igneous province of Norway.
igneous
Troctolite
A mafic plutonic rock of plagioclase and olivine whose mottled appearance earned it the nickname 'troutstone'.
igneousRogue River Jasper
An Oregon picture jasper from the Rogue River area showing earthy scenic patterns in tan, brown, gold, and cream.
mineral
Oolite
A limestone made of tiny spherical ooids, resembling fish roe, formed in warm, agitated shallow seas.
sedimentary
Serpentinite
A green, often mottled metamorphic rock formed by the hydration of mantle rocks, soft and waxy with a smooth, slippery feel.
metamorphicKiwi Jasper
A speckled green-and-black stone resembling kiwi fruit, technically a quartz-amazonite aggregate rather than true jasper.
mineralSonoran Sunset Jasper
A vivid copper-bearing Mexican stone of red cuprite and green chrysocolla that evokes a desert sunset.
mineral
Lapis Lazuli
An intensely blue metamorphic rock of lazurite flecked with golden pyrite, prized for millennia as a gemstone and ultramarine pigment.
metamorphic
Tourmaline Schist
A foliated schist threaded with black tourmaline (schorl) needles, marking boron-rich metamorphic or metasomatic conditions.
metamorphic