Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Asphalt Rock
A porous sedimentary rock naturally saturated with bitumen, dark, tarry-smelling, and historically mined for paving.
sedimentary
Porcelanite
A hard, fine-grained siliceous rock with a dull porcelain-like texture, intermediate between soft diatomite and dense chert.
sedimentarySnakeskin Jasper
An opaque patterned jasper named for its scaly, snakeskin-like surface markings of interlocking tan and brown cells.
mineralCalico Obsidian
A mottled, multicolored obsidian blending black, brown, grey, and tan patches like a calico cat's patchwork coat.
igneous
Cat's Eye Tourmaline
Tourmaline displaying chatoyancy, a moving band of light caused by parallel tube-like inclusions, when cut as a cabochon.
gemstone
Cat's Eye Beryl
Beryl displaying chatoyancy, a bright moving band of light, caused by parallel tube-like inclusions when cut as a cabochon.
gemstone