Amazonite: Amazonite is a blue-green variety of microcline feldspar, named after the Amazon River (though ironically not found there). Its distinctive color comes from lead and water content. Popular in ancient Egypt and pre-Columbian Central/South America, it's now mainly mined in Colorado, Brazil, and Russia. The stone displays white streaks and can range from bright turquoise to deep green-blue. (read full)

Microcline: Microcline is a silicate of potassium and aluminum, and an alkali member of the feldspar group. It is the phase of this compound that is stable at low temperature. The feldspars are major constituents of the rocks on the earth's crust and comprise some of the most important rock-forming minerals. The four feldspars - orthoclase, sanidine, microcline and anorthoclase - comprise a group called the (read full)

Orthoclase: Orthoclase mineral is a silicate of potassium and aluminum, belonging to the Feldspar group. It has the same composition as microcline, but is stable at slightly higher temperatures. It occurs as prismatic, sometimes flat-sided crystals, but in rocks it is usually anhedral. It may be perfectly transparent and yellow or almost colorless, but it is more often semi-opaque and white to grayish-white, (read full)

Moonstone: The variety name Moonstone is usually used to describe an optical effect and unlike most variety names it is not confined to a single species (The term is also applied to albite-moonstone, microcline-moonstone, labradorite-moonstone). But Moonstone most prominently refers to the orthoclase feldspar, Adularia Moonstone, a microperthitic association of orthoclase and albite) and rarely to Albite M (read full)