Amazonite

Hardness: 6-6.5 on Mohs scale. Color: Green to blue-green, sometimes with white streaks. Luster: Vitreous (glassy). Crystal Structure: Triclinic. Cleavage: Good in two directions at nearly 90 degrees. Specific Gravity: 2.56-2.58.

Amazonite forms in igneous rocks, particularly granite and granitic pegmatites. It can also be found in some metamorphic rocks and hydrothermal veins. Its characteristic blue-green color is thought to be due to small amounts of lead within its crystal structure. Geological age varies depending on the host rock, but it is found in formations from various geological periods.

Amazonite is primarily used as a gemstone in jewelry, often cut into cabochons, beads (as seen in the image), and polished stones. It is also used for ornamental purposes and sometimes for carved objects. Due to its relative softness, it is less common in industrial applications.

Despite its name, amazonite is not typically found in the Amazon River basin. It was likely named after the Amazon River because green stones found there were once mistaken for amazonite. It is sometimes called 'Amazon Stone.' It is often associated with other minerals like smoky quartz, albite, and cleavelandite.

Amazonite can be identified in the field by its distinctive blue-green color, vitreous luster, and crystal habit (though well-formed crystals are less common than massive forms). Its hardness (scratches glass) and presence in granitic environments are also good indicators. It is commonly found in Russia (Ilmen Mountains), Colorado (Pikes Peak), Virginia, Brazil, India, Madagascar, and Namibia. Tips for collectors include looking for it in pegmatite formations and checking for its characteristic color and cleavage.