Feldspar Mineral Group

The Feldspar group of minerals is one of the most abundant and important in the Earth's crust, comprising nearly 60% of terrestrial rocks.  Feldspars are recognized for their range of colours—from white and grey to pink, red, and green—often seen in igneous, metamorphic, and sedimentary rocks.

This diverse group includes several related minerals, such as orthoclase, plagioclase, and microcline-

  • Orthoclase is a potassium-rich feldspar that forms in a crystal structure called monoclinic. It's commonly found in granite and comes in colours like white or pink. It is used in the making of porcelain and as a gemstone in its transparent form, known as moonstone.

  • Plagioclase is a group of feldspars that have a mix of sodium and calcium. These minerals form in a triclinic crystal structure, which gives them a slightly different shape. They often have fine lines on their surfaces and are found in many types of rocks. This series includes minerals like labradorite and andesine.

  • Microcline is similar to orthoclase in being rich in potassium, but it forms in a triclinic structure, giving it a different internal pattern. It's known for its green or blue-green variety called Amazonite.

So, while orthoclase and microcline are both potassium feldspars, they have different crystal structures. Plagioclase is different because it contains both sodium and calcium and also has a distinct crystal structure.