Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Pigeon Blood Agate
A richly colored red banded agate prized by lapidaries for its deep crimson-to-brown tones reminiscent of pigeon's blood.
gemstoneSea Sediment Jasper
A colorful trade-name material, often dyed and reconstituted, sold as jasper; vivid blues and greens are typically artificially enhanced.
mineral
Bloodstone
A dark green chalcedony speckled with blood-red spots of iron oxide, traditionally known as heliotrope.
gemstone
Chalcedony
A waxy, translucent microcrystalline form of quartz that serves as the parent group for agate, jasper, carnelian, and onyx.
mineralOrca Agate
A bold black-and-white banded chalcedony named for its orca-like coloring, popular as carvings and statement jewelry.
gemstone
Geode
A hollow rock nodule whose interior cavity is lined with inward-pointing crystals such as quartz, amethyst, or calcite.
mineral
Menilite Opal
An opaque grey-brown common opal forming nodules and concretions, historically called liver opal for its dull brownish color.
mineral
Chrome Chalcedony
A vivid green chalcedony colored by chromium, often called mtorolite, resembling chrysoprase but owing its color to chromium rather than nickel.
gemstone
Seam Agate
Agate that forms in flat cracks or veins of host rock rather than rounded nodules, producing straight, parallel banding.
gemstone
Tube Agate
A chalcedony agate containing hollow or mineral-filled tubes that appear as rods, circles, or pipes depending on the angle of the cut.
gemstone
Moss Agate
A translucent chalcedony filled with green or brown dendritic mineral inclusions that resemble moss, foliage, or landscapes.
gemstone
Blue Jasper
An opaque blue variety of chalcedony jasper, less common than red or green forms, colored by mineral inclusions.
mineral
Eye Agate
A chalcedony agate marked by round, concentric ring patterns that resemble eyes when cut and polished.
gemstone
Poppy Jasper
An orbicular jasper with red and orange flower-like spots resembling poppies, famously from Morgan Hill, California.
mineral
Plume Agate
A translucent agate containing delicate three-dimensional feather- or plant-like plumes of mineral inclusions suspended in chalcedony.
gemstone
Owyhee Jasper
A picture jasper from the Owyhee region of Oregon and Idaho, prized for scenic tan, cream, and blue-grey landscape patterns.
mineralCarver Agate
A collectible Oregon plume and scenic agate with feathery red and gold inclusions suspended in translucent chalcedony.
gemstoneApricot Agate
A soft peachy-orange variety of banded chalcedony, naturally iron-tinted or dyed, popular for warm-toned beads and jewelry.
gemstone
Flower Jasper
A jasper whose radiating mineral clusters form flower-like rosettes scattered across an earthy background.
mineral
Biggs Jasper
A classic Oregon picture jasper showing layered tan, brown, and blue-grey scenes resembling desert landscapes and canyons.
mineral
Laguna Agate
A highly prized Mexican fortification agate from Chihuahua, famed for vivid red and orange banding with tight, intricate patterns.
gemstone
Tree Agate
A white chalcedony filled with green or black dendritic, tree-like mineral inclusions that resemble ferns or moss frozen in stone.
gemstoneUnakite Jasper
An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.
metamorphic
Bruneau Jasper
A prized Idaho picture jasper from Bruneau Canyon known for brown and cream orbicular egg-rock patterns and scenic landscapes.
mineral