Rock & Mineral Encyclopedia

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

Garnet Schist

A shiny, foliated schist studded with red garnet crystals that grew during medium-grade regional metamorphism.

A rosette-shaped cluster of bladed gypsum or barite crystals that traps sand, forming flower-like formations in arid deserts.

The common iron-rich black variety of tourmaline, by far the most abundant tourmaline species and a popular grounding crystal.

A translucent apple-green chalcedony colored by nickel, the most prized green variety of the quartz family.

A banded variety of chalcedony quartz, classically black or black-and-white, long favored for cameos and beads.

Tourmaline crystals displaying two or more distinct colors at once, including the famous pink-and-green watermelon variety.

A pink, manganese-rich variety of zoisite used as an ornamental gemstone, often mottled with white quartz and grey matrix.

The opaque black iron-rich variety of tourmaline (schorl), forming striated prismatic crystals popular as a protective grounding stone.

A striking platy, blade-like variety of albite feldspar that grows in fanned aggregates of thin white crystals within granite pegmatites.

Black volcanic glass laced with delicate web-like veins of contrasting color, formed by flow banding and fine crystallization.

Black volcanic glass marked with rounded spots and patches that resemble a leopard's coat, caused by spherulitic crystallization.

A pale chalcedony agate with cloudy, frost-like white patterning suggesting frost on a window or icy crystalline textures.

A dark, foliated schist rich in graphite that leaves a grey-black mark and forms from metamorphosed carbon-rich sediments.