Rock & Mineral Encyclopedia

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

Green Calcite

A soft mint-to-apple-green variety of calcite, a common calcium carbonate mineral popular as soothing tumbled stones.

An affordable multicolored banded and mossy chalcedony from India, common in tumbled stones, beads, and meditation pieces.

A soft, soothing powder-blue variety of calcite, a common calcium carbonate mineral often sold as gentle tumbled stones.

A brecciated, chatoyant quartz with swirling blue, gold, and brown fibers that shimmer like a stormy sky.

A common coarse-grained intrusive rock like granite but richer in plagioclase than potassium feldspar.

A patterned common opal with mottled, leopard-like spots and blotches, prized as an ornamental and cabochon stone.

A common opal with branching, tree-like mineral inclusions that create natural fern, moss, or landscape patterns.

A common opal containing moss- or fern-like mineral inclusions that resemble plants suspended in a pale silica body.

A common opal containing dendritic or mossy mineral inclusions that form miniature landscape-like scenes inside the stone.

Tourmaline displaying chatoyancy, a moving band of light caused by parallel tube-like inclusions, when cut as a cabochon.

An opaque, porcelain-white common opal prized for its milky, pearl-like appearance and high porosity, often carved or beaded.

An opaque to translucent milky-white common opal valued for its soft porcelain-like color rather than play-of-color.

An opal cut to show chatoyancy, a sharp moving band of light like a cat's eye, usually in honey, green or yellow common opal.

Beryl displaying chatoyancy, a bright moving band of light, caused by parallel tube-like inclusions when cut as a cabochon.