Feldspar

Feldspar is a silicate and is the most abundant of the minerals constituting a reported 60% of the earth’s crust. If you were to run it up through the classification system, you’d find Feldspar is a part of the triclinic and monoclinic crystal systems. Feldspar generally falls into one of two camps – plagioclase, rich in sodium and calcium, or alkali feldspar, rich in potassium…all depending on their origins. Plagioclase tend to be derived from the melting of Earth’s mantle while alkali typically derives from the melting of crystal rocks (like granite). These are not mutually exclusive and do crossover quite a bit so if you are looking to understand on a super deep level there are lots of variables to look at.

Feldspars variables are temperature, Na:Ca vs K, and miscibility gaps. The following stones are all considered Feldspars:

• Amazonite
• Orthoclase
• Albite
• Sunstone
• Moonstone
• Larvikite
• Labradorite