Minerals & Gemstone 480x104
Minerals & Gemstone 480x104
wpdiamonds.com
Minerals V2 banner 160x600



Advertising Information

perthite

Perthite is an intergrowth of two different Feldspar minerals in one rock. Perthite is usually composed of veins or stripes of one feldspar running through a different feldspar. There are many different types of Perthite. Perthite combinations are of Albite (and sometimes Oligoclase) intermixed with either Microcline or Orthoclase.



Types of Perthites:


Classified by Host:

  • Antiperthite - Perthite in which the potassium feldspar (i.e. Microcline and Orthoclase) forms first, and afterwards the sodium feldspar (i.e. Albite and Oligoclase) forms internally in the mineral.
  • Mesoperthite - Perthite in which the sodium feldspar (i.e. Albite and Oligoclase) forms first, and afterwards the potassium feldspar (i.e. Microcline and Orthoclase) forms internally in the mineral.

Classified by Size:
  • Cryptoperthite - Perthite in which the feldspar intergrowth is so fine it can only be detected with a microscope.
  • Microperthite - Perthite in which the feldspar intergrowth is very fine but it can be detected with an unaided eye.
  • Macroperthite - Perthite in which the feldspar intergrowth is large and is easily seen.

Classified by Type:


< Back