Rock & Mineral Encyclopedia

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

Apache Tears

Rounded nodules of translucent obsidian, named after a Native American legend, that glow smoky brown when held to light.

A glassy, jet-black volcanic rock formed when lava cools too fast to crystallize, prized for razor-sharp conchoidal edges.

Jet-black natural volcanic glass formed by rapidly cooled lava, prized for its glassy luster and razor-sharp conchoidal fracture.

Small, smooth, teardrop-shaped beads of basaltic volcanic glass formed from airborne lava droplets, often paired with Pele's hair.

A deep teal glass sold as obsidian; the saturated blue-green color is manufactured and not found in natural volcanic glass.

A sought-after elbaite tourmaline in teal hues that blend blue and green, prized for its ocean-like color.

The blue variety of tourmaline, a relatively rare and prized color ranging from teal and greenish blue to deep indigo.

Tourmaline in blue tones, encompassing iron-colored indicolite and the rare neon copper-bearing Paraiba, among the scarcer tourmaline colors.

Elbaite tourmaline spanning the blue-to-green range, from sea-green to deep peacock hues, popular for its versatile color.

A precious opal showing dominant peacock-like blue, green and teal play-of-color, often on Ethiopian material.

Tourmaline colored by copper, producing the famous vivid neon blues, greens and teals known commercially as Paraiba-type gems.

A soft blue common opal, famously from Peru, valued for its serene sky-to-teal color rather than play-of-color.