Amazonite (sometimes called "Amazon stone") is a green variety of
The name is taken from that of the
Amazon River, from which certain green stones were formerly obtained, but it is doubtful whether green feldsparoccurs in the Amazon area.
Amazonite is a mineral of limited occurrence. Formerly it was obtained almost exclusively from the area of
Miassin the Ilmen mountains, 50 miles southwest of Chelyabinsk, Russia, where it occurs in granitic rocks. More recently, high-quality crystals have been obtained from Pike's Peak, Colorado, where it is found associated with smoky quartz, orthoclase, and albitein a coarse graniteor pegmatite. Crystal Peak, Teller County, Coloradois a well-known locality for crystals of amazonite. Some other localities in the United Statesyield amazonite, and it is also found in pegmatitein Madagascar.
Because of its bright
greencolour when polished, amazonite is sometimes cut and used as a gemstone, although it is easily fractured.
For many years, the source of amazonite's color was a mystery. Naturally, many people assumed the color was due to copper because
coppercompounds often have blue and green colors. More recent studies suggest that the blue-green color results from small quantities of leadand water in the feldspar. (Hoffmeister and Rossman, 1985)
List of minerals
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