Rock & Mineral Encyclopedia

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

Rubellite

The red to raspberry-pink variety of tourmaline, prized for its vivid ruby-like color that holds under both daylight and artificial light.

A rare sky-blue variety of pectolite found only in the Dominican Republic, prized for its sea-like color and white volcanic patterning.

A pastel purple variety of common opal, valued for its gentle lilac body color rather than any play-of-color.

A pink to red gem variety of elbaite tourmaline, colored by manganese, ranging from soft pastel pink to vivid rubellite red.

The classic green gem variety of elbaite tourmaline, ranging from bright grass-green to deep forest tones colored by iron or chromium.

An exceptionally hard beryllium aluminum oxide prized for golden hues, sharp cat's-eye effect, and the rare color-change alexandrite variety.

Rutile is a major titanium ore and the famous golden needle inclusion that gives rutilated quartz its shimmering threads.

The blue color variety of beryl, ranging from pale sky tones to rich sea-blue, best known in its finest grades as aquamarine.

A jasper made of angular fragments naturally cemented back together, typically showing red and brown pieces in a quartz matrix.

A vivid blue-green hydrated copper silicate, soft on its own but prized as a gem when hardened by intergrown quartz or chalcedony.

A translucent to transparent opal in warm yellow, orange, and red tones, prized for body color rather than play-of-color.

A banded, metamorphosed iron formation in which bright red jasper alternates with silvery hematite or magnetite layers.

Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.

An old varietal name for alkali- and cesium-rich beryl, typically colorless to pale pink, overlapping with vorobyevite and morganite.

The calcium-aluminum garnet species spanning green tsavorite, cinnamon hessonite, and colorless leuco garnet — one of the most varied garnets.