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 Moonstone

A pale green variety of feldspar moonstone showing a soft white or bluish adularescent sheen over a greenish body.

A hydrated silica gemstone famous for its shimmering play-of-color, ranging from white and black opal to fiery orange fire opal.

A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.

Rutile is a major titanium ore and the famous golden needle inclusion that gives rutilated quartz its shimmering threads.