Rock & Mineral Encyclopedia

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

Aquamarine Crystal

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

A deep blue beryl whose intense color comes from radiation-induced color centers and tends to fade in light, named after the Maxixe mine in Brazil.

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

A deep blue beryl with a color caused by radiation that fades in light, named after the Maxixe mine in Brazil.

A single beryl crystal showing two distinct color zones, such as aquamarine blue grading into morganite pink, within one stone.

A hard, dark, poorly sorted sandstone with a muddy matrix, typically deposited by underwater turbidity currents.

The smoky brown to gray variety of quartz, colored by natural irradiation, valued as both a gemstone and crystal specimen.