Rock & Mineral Encyclopedia

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

Serpentine

A group of green magnesium silicate minerals with a smooth, waxy feel, often carved and sometimes sold as imitation jade.

A translucent quartz speckled with glittery mineral inclusions that produce a shimmering aventurescence, most often green.

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

A green, often mottled metamorphic rock formed by the hydration of mantle rocks, soft and waxy with a smooth, slippery feel.

Natural emerald crystals still embedded in their host rock, prized as mineral specimens that show how the gem grew in place.

A jasper marked with soft feather- or plume-like mineral inclusions that drift through a pale silica body.

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

A pale jasper threaded with black, fern-like mineral dendrites that mimic plants, trees, and frost despite being inorganic.

A white chalcedony filled with green or black dendritic, tree-like mineral inclusions that resemble ferns or moss frozen in stone.