Rock & Mineral Encyclopedia

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

Arsenopyrite

A silver-white iron arsenic sulfide and the most common arsenic mineral, known for striking sparks and a garlic smell when struck.

A scarlet-red silver arsenic sulfide known as light ruby silver, a striking but light-sensitive ore that darkens on exposure.

A bright yellow native element mineral that forms around volcanic vents and hot springs and burns with a blue flame.

A dense, soft, intensely yellow native metal valued for millennia in coinage, jewelry, and electronics.

A pale copper-red nickel arsenide, historically called kupfernickel, that is an ore of nickel and gives the metal its name.

A silver-white cobalt arsenic sulfide that is a leading ore of cobalt, forming bright metallic cubic and pyritohedral crystals.

A soft, reddish native metal with excellent conductivity, mined for wiring, plumbing, and alloys like bronze and brass.

A dense, durable, silvery-white precious metal that resists corrosion, used in fine jewelry and catalytic converters.

A soft, lustrous white native metal with the highest electrical conductivity, used in jewelry, coinage, and industry.

A vivid yellow-and-black banded stone from Indonesian volcanic vents, colored by sulfur, arsenic minerals and iron oxides, not true jasper.

A soft, fine-grained red metamorphosed claystone, sacred to many Native American peoples and carved into ceremonial pipes.

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

A metallic cobalt-nickel arsenide, an important cobalt ore, named for the Skutterud mines of Norway.

A rare platinum arsenide and the most important platinum-bearing mineral, forming bright metallic cubic crystals.

An unusually pure, transparent-to-translucent obsidian with few inclusions; truly water-clear specimens are rare in nature.