Rock & Mineral Encyclopedia

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

Ruby

The red, chromium-colored variety of corundum, prized as one of the most valuable colored gemstones and second only to diamond in hardness.

A striking rock of green zoisite studded with red-pink ruby crystals and black hornblende, also called anyolite.

The soft pink, usually cloudy variety of quartz colored by trace titanium or microscopic inclusions, popular for carvings and beads.

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

A translucent red opal, closely related to Mexican fire opal, glowing with a warm cherry-red body color often free of play-of-color.

Vivid red to raspberry tourmaline, the most intense colors are marketed as rubellite, colored by manganese in the elbaite structure.

Montana Garnet is red almandine recovered from Montana placer gravels, often alongside the state's famous sapphires.