Rock & Mineral Encyclopedia

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

Snow Quartz

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

Iron-stained sandstone whose red color comes from hematite coatings, formed in oxidizing desert, river, and coastal environments.

An orange-to-rust colored variety of natural volcanic glass whose warm tone comes from iron oxide staining within the obsidian.

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 pegmatitic granite in which quartz and feldspar intergrow to resemble ancient runic or Hebrew script.

A chromium-rich pyrope garnet whose intense blood-red color comes from chromium, often mined from ant hills and kimberlite weathering.

A deep blue beryl whose intense color comes from radiation-induced color centers and tends to fade in light, named after the Maxixe mine in Brazil.