Amazonite is a mineral that is typically a greenish blue, greenish white or greenish yellow color. It is composed primarily of microcline, a potassium-rich feldspar mineral.

Amazonite forms through the process of hydrothermal alteration or metamorphism of rocks that contain potassium-rich feldspar minerals. These processes can cause the feldspar minerals to change and form amazonite.

Amazonite can be found in a variety of rock types, including granite, gneiss, and pegmatite. It is typically found in areas that have undergone hydrothermal alteration or metamorphism in the past.

The history of amazonite can be traced back to ancient civilizations, who valued it as a gemstone. The ancient Egyptians, for example, used amazonite as a decorative stone. Amazonite was also believed to have healing properties and was used in ancient medicine.

In terms of age, Amazonite is considered a medium-age mineral, forming in metamorphic rocks during the middle or late geological period, so it age can range from millions to hundreds of millions of years.