Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Cape Ruby
Cape Ruby is a deep red pyrope garnet from South African diamond deposits, prized as an affordable, fiery alternative to ruby.
gemstone
Lamprophyre
A dark, mineral-rich dike rock with abundant mica or amphibole phenocrysts set in a fine groundmass, often associated with gold and diamonds.
igneous
White Beryl
The colorless to milky-white variety of beryl, known mineralogically as goshenite and once used to imitate diamond and other gems.
gemstone
Lamproite
A rare ultrapotassic, magnesium-rich volcanic rock from deep in the mantle, famous as the diamond host at Argyle in Australia.
igneous
Rose Tourmaline
A soft to medium pink elbaite tourmaline in rose hues, colored by manganese and prized for romantic jewelry.
gemstoneSilver
A soft, lustrous white native metal with the highest electrical conductivity, used in jewelry, coinage, and industry.
mineral
Gold
A dense, soft, intensely yellow native metal valued for millennia in coinage, jewelry, and electronics.
mineral
Jasper
An opaque, often colorfully patterned variety of chalcedony quartz, popular for tumbling, carving, and jewelry.
mineral
Titanite
A calcium titanium silicate, gem-known as sphene, famous for fiery dispersion that exceeds diamond and rich green-to-yellow colors.
gemstone
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
Eye Agate
A chalcedony agate marked by round, concentric ring patterns that resemble eyes when cut and polished.
gemstone
Green Opal
A common opal colored green by nickel or chromium impurities, usually opaque and cut into cabochons and beads.
gemstone
Blood Agate
A deep red banded agate colored by iron oxides, valued as a vivid red lapidary and jewelry stone.
gemstone
Hessonite Garnet
The cinnamon-to-honey colored variety of grossular garnet, prized in jewelry and revered as the gem 'gomed' in Vedic astrology.
gemstone
Platinum
A dense, durable, silvery-white precious metal that resists corrosion, used in fine jewelry and catalytic converters.
mineral
Spencer Opal
Precious opal from Spencer, Idaho, occurring in thin colorful seams that are typically cut into triplets.
gemstoneCat's Eye Labradorite
A labradorite feldspar cut to show a moving band of light (chatoyancy), sometimes combined with labradorescent color flashes.
gemstone
Pyrope Garnet
The magnesium-rich garnet famed for its intense blood-red 'fire,' historically the Bohemian garnet of Victorian jewelry.
gemstone
Black Agate
A deep black variety of banded chalcedony, often closely related to or treated like onyx, used for jewelry and carvings.
gemstone
Rainbow Obsidian
A black volcanic glass that reveals concentric rainbow bands of color when cut and polished against the light.
igneous
Melanite Garnet
The titanium-rich black variety of andradite garnet, with a brilliant resinous luster prized for mourning and statement jewelry.
gemstone
Cat's Eye Tourmaline
Tourmaline displaying chatoyancy, a moving band of light caused by parallel tube-like inclusions, when cut as a cabochon.
gemstone
Cat's Eye Green Tourmaline
Green tourmaline cut as a cabochon to show a sharp moving band of light (chatoyancy) caused by fine parallel inclusions.
gemstone
Iris Agate
A banded agate that diffracts transmitted light into rainbow colors when cut thin and backlit, producing a spectacular iridescence.
gemstone