Rock & Mineral Encyclopedia

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

Blue Apatite

A blue calcium phosphate mineral with vivid color and middling hardness, the same mineral family that forms bones and teeth.

A banded variety of chalcedony quartz, famed for its colorful concentric layers and enormous range of patterns and colors.

An opaque yellow-to-golden variety of jasper, an iron-stained microcrystalline quartz prized for warm color and durable polish.

Clear quartz coated with orange-red hematite, giving points a vivid tangerine color, mainly from Brazil.

A rare calcium-rich lithium tourmaline famous for the spectacular concentric color zoning seen in polished cross-section slices.

A vivid greenish-yellow quartz, usually heat-treated or irradiated, prized for its clean clarity and bright lemon color.

An opaque, snow-white variety of quartz whose milky color comes from countless tiny gas and fluid inclusions.

An extremely common calcium carbonate mineral that comes in nearly every color and shows strong double refraction in clear crystals.

A translucent, soft blue variety of microcrystalline quartz whose color comes from light scattering through its fine structure.

A hard aluminum borosilicate famous for its rich denim-blue color, often forming dense fibrous masses or coloring quartz blue.

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.