Rock & Mineral Encyclopedia

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

Amazonite

The blue-green gem variety of microcline feldspar, often mottled with white, prized as an affordable ornamental stone.

A speckled green-and-black stone resembling kiwi fruit, technically a quartz-amazonite aggregate rather than true jasper.

A finely speckled pale jasper trade stone named for its sesame-seed-like flecks, closely related to Kiwi Jasper.

A common potassium feldspar identical in composition to orthoclase but more ordered, famous for its green gem variety amazonite.

Fossil shells whose original material has been replaced by opal, preserving ancient marine forms in common or precious opal.