Is additional orthoclase a metastable phase variant?

Orthoclase is a metastable phase variant of potassium feldspar and an insoluble potassium salt mineral.

The structural state of potassium feldspar is low orthoclase, followed by medium orthoclase, and a few are medium microcline. Potassium feldspar is generally flesh-red, yellow-white, white or gray. Potassium feldspar crystals are often in the shape of short columns or thick plates, with glass luster, a specific gravity of 2.56, a Mohs hardness of 6, and a melting point of 1290°C.There are two homogeneous polymorphs of orthoclase which is feldspar and microcline.

Orthoclase is the main raw material for the ceramic industry and the glass industry, of which the glass industry ac s for about 50 to 60% of the total consumption. The usage of orthoclase in the ceramic industry ac s for 30%. In addition, the mineral orthoclase can also be used to prepare potash fertilizer. Better quality potassium feldspar is used to make television imaging glass bulbs.