Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Needle Tourmaline
Fine acicular (needle-like) tourmaline crystals, often black schorl, frequently seen as slender inclusions within clear quartz.
mineral
Color-Change Tourmaline
A rare tourmaline that visibly changes color between daylight and incandescent light, similar to the alexandrite effect.
gemstone
Color Change Garnet
A rare garnet that dramatically shifts color from greenish in daylight to reddish under lamplight, rivaling alexandrite.
gemstone
Baddeleyite
A natural zirconium dioxide mineral, hard and refractory, valued as a zirconium source and prized for high-precision U-Pb dating.
mineral
Ruby
The red, chromium-colored variety of corundum, prized as one of the most valuable colored gemstones and second only to diamond in hardness.
gemstone
Bohemian Garnet
Small, intensely red chrome-pyrope garnets from the Czech Bohemian region, famous for densely set antique Victorian jewelry.
gemstone
Milky Quartz
The most common variety of quartz, milky white from microscopic fluid and gas inclusions, forming massive veins worldwide.
crystal
Chevron Amethyst
A naturally banded quartz combining purple amethyst and white quartz in striking V-shaped chevron or zigzag patterns.
crystalOrca Agate
A bold black-and-white banded chalcedony named for its orca-like coloring, popular as carvings and statement jewelry.
gemstone
Laguna Agate
A highly prized Mexican fortification agate from Chihuahua, famed for vivid red and orange banding with tight, intricate patterns.
gemstone
Radiolarite
A hard, fine-grained siliceous rock built from the microscopic silica skeletons of radiolarians, often forming colorful ribbon-banded cherts.
sedimentary
Smoky Quartz
The smoky brown to gray variety of quartz, colored by natural irradiation, valued as both a gemstone and crystal specimen.
crystal
Indian Agate
An affordable multicolored banded and mossy chalcedony from India, common in tumbled stones, beads, and meditation pieces.
gemstone
Scepter Quartz
Quartz with a wider crystal 'cap' that grew over a narrower stem, forming a natural scepter or mushroom shape.
crystal
Spirit Quartz
A South African quartz whose central crystal is coated in tiny druzy points, also called cactus or fairy quartz.
crystal
Star Rose Quartz
Rose quartz that displays a six-rayed star (asterism) when cut as a cabochon, caused by microscopic rutile-like inclusions.
gemstoneAmegreen
A natural bicolor quartz blending amethyst purple with prasiolite green in a single crystal, prized as a metaphysical heart-crown stone.
crystal
Lemon Quartz
A vivid greenish-yellow quartz, usually heat-treated or irradiated, prized for its clean clarity and bright lemon color.
crystal
Montana Moss Agate
A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.
gemstone
Rose Quartz
The soft pink, usually cloudy variety of quartz colored by trace titanium or microscopic inclusions, popular for carvings and beads.
crystal
Uraninite
Uraninite is the chief radioactive uranium ore, a dense black oxide and the historic source of radium and uranium.
mineral
Flower Agate
A creamy pink-and-white chalcedony from Madagascar containing flower-like plume inclusions that resemble blossoms suspended in stone.
gemstone
Morion Quartz
The darkest, near-opaque black variety of smoky quartz, colored by natural radiation acting on trace aluminum.
crystalApricot Agate
A soft peachy-orange variety of banded chalcedony, naturally iron-tinted or dyed, popular for warm-toned beads and jewelry.
gemstone