The no less than forty varieties of feldspars are crystalline aluminosilicate minerals. They form in all types of situations including metamorphic, igneous and sedimentary. As one of the Earth's major building blocks, basic feldspar changes a bit when it occurs with other minerals such as calcium, sodium and/or barium. Those of you who did not have to click above to look up the definition of aluminosilicate are probably very experienced in working with different types of glass or clay glazes that are made of ground feldspar containing potassium, as the potassium really revs up colors.

Basic feldspar is used in so many ways that you probably use something made with feldspar every day and don't know it! Ground feldspar is used in making toothpaste, scouring powder, electrical insulators, and some types of dental work. Industrial producers of glass and ceramic products add feldspar to silica mixtures as a flux to keep the boiling point down. Feldspar is also used as a filler in rubber, paper, and plastic products as well as in paints and fertilizers. There are so many more processes and products that include the use of feldspar that I really don't have the space to list them all here. By the way, did you know that a specimen of feldspar was even brought back from the Earth's moon by Apollo 16? Check it out, Lunar Feldspar - amazing!

There are so many types of feldspars that they have been broken down into several smaller groups or classes, by their slight differences in composition. The two groups that contain the gem-rocks that we wire artists are most interested in are those that exhibit schillers of light, Orthoclase and Plagioclase. In this first article on feldspar, I am going to tell you a bit about the one Microcline gem-rock form of feldspar, that we all know better as amazonite, or amazonstone.