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.

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

The blue iron-bearing variety of beryl, forming clear hexagonal crystals prized both as specimens and as a March birthstone gem.

The natural crystalline form of emerald, the prized green chromium-and-vanadium variety of beryl and the May birthstone.

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

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

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.

The natural crystal form of morganite, the manganese-colored pink-to-peach variety of beryl popular in romantic jewelry.

A striking lead chromate mineral prized for its brilliant orange-red prismatic crystals, with the finest specimens from Tasmania.

A medium-grade metamorphic rock rich in aligned platy minerals that gives it a shiny, easily splitting, foliated texture.

Quartz colored blue by inclusions of the mineral dumortierite, giving a denim-like blue ornamental stone harder than dumortierite alone.

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

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

A white chalcedony filled with green or black dendritic, tree-like mineral inclusions that resemble ferns or moss frozen in stone.