Amazonite

Amazonite is the green to blue-green gem variety of microcline, a potassium feldspar. Its distinctive colour is linked to traces of lead together with structural water and is unusual among feldspars; the name comes from the Amazon River, although the original material is thought not to have come from there.

Properties

Microcline is triclinic, hard (6–6.5) and shows two cleavages meeting at close to 90 degrees. Amazonite is typically translucent to opaque and frequently shows a white grid-like (gridiron) pattern from intergrown albite, which can give a pleasing sheen when polished.

Occurrence

Fine amazonite comes from the granite pegmatites of the Pikes Peak region in Colorado — often perched with smoky quartz — as well as from Russia, Madagascar, Brazil and Ethiopia. It belongs to the feldspar group.