Rock & Mineral Encyclopedia

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

Fire Opal

A translucent to transparent opal in warm yellow, orange, and red tones, prized for body color rather than play-of-color.

A chalcedony agate with red, orange, and yellow plume or banding patterns that rise like dancing flames within the stone.

A banded rhyolitic volcanic rock with swirling tan, red, and yellow iron-oxide layers prized as a decorative picture stone.

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