Rock & Mineral Encyclopedia

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

Moss Opal

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

A rounded sedimentary nodule cracked internally and filled with veins of yellow calcite, prized for its striking dragon-skin patterning.

A hard, fine-grained siliceous rock with a dull porcelain-like texture, intermediate between soft diatomite and dense chert.

A vivid Australian jasper-like silica stone in earthy reds, yellows, and purples, formed from silicified radiolarian sediment.

A rare, prized Oregon picture jasper known for blue-green orbs and scenic patterns, often called the king of jaspers.

A prized Mexican jasper known for pastel green, lavender, and cream orbicular patterns that take an exceptional polish.

A jasper crossed by fine dark veins forming a spiderweb-like network, often a brecciated stone cemented by darker matrix.

An Australian silicified radiolarite jasper in warm mustard, red, burgundy, and cream earth tones, found only in Western Australia.

A dark green jasper-chalcedony speckled with red iron-oxide spots, classically known as bloodstone or heliotrope.

A rare Australian jasper from the Pilbara with bold red, yellow, and black abstract patterns, prized by collectors.