Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Lake Huron Agate
Glacially transported banded agates found along Lake Huron's shores, typically small, frosted pebbles with red-orange iron banding.
gemstone
Lake Michigan Agate
Glacially deposited banded agates found along Lake Michigan beaches, small waterworn pebbles with concentric red and grey banding.
gemstone
Carey Plume Agate
A prized plume agate from near Carey, Idaho, showing red, pink and black feathery plumes floating in translucent chalcedony.
gemstone
Holley Blue Agate
A rare translucent lavender-blue agate from the Holley area of Oregon, prized for its soft purple-blue color.
gemstone
Crowley Ridge Agate
Agate found in the gravels of Crowley's Ridge in northeastern Arkansas, a stream-transported banded chalcedony.
gemstone
Snake Skin Agate
A chalcedony with a distinctive scaly, reptile-skin surface texture, typically in pale tan, pink, and gray tones.
gemstone
Blue Lace Agate
A soft sky-blue banded chalcedony prized for its delicate, lace-like white and blue swirling patterns.
gemstone
Pigeon Blood Agate
A richly colored red banded agate prized by lapidaries for its deep crimson-to-brown tones reminiscent of pigeon's blood.
gemstone
Owyhee Blue Agate
A soft sky-blue chalcedony from the Owyhee region of Oregon and Idaho, prized for its calming, opaque powder-blue color.
gemstone
Montana Moss Agate
A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.
gemstone
Dragon Vein Agate
A treated chalcedony with a network of crackled veins, usually heated and dyed in vivid colors for affordable, eye-catching beads.
gemstone
Teepee Canyon Agate
A fortification agate from the Black Hills of South Dakota, known for tight, colorful banding closely related to the famous Fairburn agate.
gemstone
Crazy Lace Agate
A Mexican banded agate famous for tightly swirling, contorted lacy patterns in warm reds, creams, and golds.
mineral
Swazi Lace Agate
A swirling, intricately banded lace agate from Eswatini (Swaziland) in soft greys, blues and lavenders with delicate folded patterns.
gemstone
Mexican Lace Agate
A vividly swirling banded agate from northern Mexico with intricate looping patterns in warm reds, golds and creams.
gemstone
Lemurian Seed Quartz
Clear quartz crystals marked by distinctive horizontal ladder-like striations, popularized from Brazil as a metaphysical stone.
crystal
Star Rose Quartz
Rose quartz that displays a six-rayed star (asterism) when cut as a cabochon, caused by microscopic rutile-like inclusions.
gemstone
Golden Healer Quartz
Quartz colored or coated by golden iron oxides such as limonite or goethite, giving a warm sunlit yellow glow.
crystal
Lake Superior Agate
A glacier-transported banded agate from the Lake Superior region, colored by iron into rich reds and oranges, and Minnesota's state gemstone.
gemstone
Quartz-mica Schist
A foliated metamorphic rock of interlayered quartz and mica, producing a sparkling, easily split rock from metamorphosed sandy shales.
metamorphic
Carnelian
A warm orange-to-red variety of chalcedony quartz colored by iron oxide, used since antiquity for seals, beads, and cabochons.
gemstone
Gem Silica
A rare, intensely blue chalcedony colored by copper-rich chrysocolla, prized as the most valuable of the blue chalcedonies.
gemstone
Black Onyx
A solid jet-black chalcedony, usually a dyed and treated agate, prized for sleek polished beads, cabochons, and intaglios.
gemstone
Prase
An old name for a dull leek-green variety of quartz or chalcedony colored by green mineral inclusions, historically called mother of emerald.
crystal