Rock & Mineral Encyclopedia

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

Blue Apatite

A blue calcium phosphate mineral with vivid color and middling hardness, the same mineral family that forms bones and teeth.

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

An opaque blue variety of chalcedony jasper, less common than red or green forms, colored by mineral inclusions.

The serene blue-to-sea-green variety of beryl, aquamarine is a durable gemstone colored by trace iron and birthstone for March.

Aquamarine crystals still attached to their natural host rock, prized as mineral specimens showing beryl in its original pocket setting.

Natural emerald crystals still embedded in their host rock, prized as mineral specimens that show how the gem grew in place.

A translucent quartz speckled with glittery mineral inclusions that produce a shimmering aventurescence, most often green.

A deep blue copper carbonate mineral that forms in oxidized copper deposits, often alongside green malachite.