Amazonite

Hardness: 6 to 6.5 on the Mohs scale. Color: Typically blue-green to green, ranging from pale to vibrant. Luster: Vitreous to pearly. Crystal Structure: Triclinic system, often forming prismatic crystals, but also massive, granular, or tabular habits. Cleavage: Good in two directions at nearly 90 degrees. Specific Gravity: 2.56-2.58.

Amazonite is a tectosilicate mineral that forms in granitic igneous rocks (especially pegmatites), and occasionally in some metamorphic rocks and hydrothermal veins. Its characteristic blue-green color is believed to be due to small amounts of lead within its crystal structure, rather than copper as often thought. It typically forms at relatively high temperatures and pressures within the Earth's crust. Its geological age varies depending on the host rock formation, often found in ancient Precambrian to Cenozoic-era pegmatites.

Amazonite is primarily used as a gemstone and ornamental stone. It is cut into cabochons, beads, and carved into various decorative objects. Due to its attractive color, it is popular in jewelry. Lesser quality material may be used in architectural applications or as decorative aggregates.

Amazonite is named after the Amazon River, although ironically, it is not found there. The earliest known source was in the Ilmensky Mountains of Russia. It was highly valued by ancient Egyptians, who used it for jewelry, carvings, and inlays. Sometimes referred to as 'Amazon Stone.' It is a member of the microcline family, which in turn is a type of feldspar.

In the field, amazonite is identified by its distinctive blue-green color, its white streak, and its characteristic feldspar cleavage (two directions at nearly right angles). It's often found in association with quartz, albite, and mica in granitic pegmatites. Common localities include Russia (Ilmensky Mountains), United States (Colorado, Virginia, Pennsylvania), Brazil, Madagascar, and Namibia. For collectors, well-formed crystals with intense color are most desirable. Be cautious of fakes or dyed imitations, which can sometimes be mistaken for natural amazonite.