Rock Identifier

Rock & Mineral Encyclopedia

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

Honey Opal

A warm golden-to-amber opal ranging from translucent common opal to precious stones that flash play-of-color over a honey body.

gemstone

Mintabie Opal

Precious opal from the Mintabie field in South Australia, known for hard, bright crystal opal and some dark-bodied stones.

gemstone
Gold Opal

Gold Opal

A golden-toned opal ranging from translucent common opal to precious stones flashing color against a warm yellow body.

gemstone

Flame Opal

A glowing orange-to-red opal whose warm body color resembles flame; some stones add flashes of play-of-color.

gemstone

Particolored Tourmaline

A tourmaline displaying two or more distinct colors in a single crystal, prized for natural color zoning like watermelon and bicolor stones.

gemstone
Coober Pedy Opal

Coober Pedy Opal

Australia's classic light-bodied precious opal from Coober Pedy, famed for milky white stones flashing pastel rainbow play-of-color.

gemstone

Syrian Garnet

Syrian Garnet is an old trade name for fine deep-red almandine, historically tied to the Syriam region and prized as 'precious garnet.'

gemstone
Orthoclase

Orthoclase

A common rock-forming potassium feldspar, the Mohs hardness reference at 6, found in granites and used in ceramics and glassmaking.

mineral
Spinel

Spinel

A durable magnesium aluminum oxide gem that occurs in many colors and was long mistaken for ruby.

gemstone
Precious Opal

Precious Opal

The classic gem opal that flashes shifting spectral colors, defined by the diffraction effect known as play-of-color.

gemstone
Black Opal

Black Opal

The rarest and most valuable opal, with a dark body tone that makes its flashing rainbow play-of-color blaze brilliantly.

gemstone
White Opal

White Opal

The most common precious opal, with a pale milky body that shows softer pastel flashes of play-of-color throughout.

gemstone
Australian Opal

Australian Opal

Opal from Australia, the world's leading source of precious opal, ranging from white and crystal to prized black and boulder types.

gemstone
Thunderegg Agate

Thunderegg Agate

A nodular rhyolite geode-like ball whose plain exterior hides a star-shaped agate or chalcedony core when cut.

gemstone