Yellow Orthoclase Feldspar

The yellow variety of orthoclase feldspar is generally faceted like a step-cut, since the stones in many cases are fragile. The yellow colour is a result of the existence of iron. Orthoclase crystals are columnar or tabular prisms, and therefore are often twinned.The very best yellow orthoclase can be found in Madagascar in pegmatites, and could be faceted for that collector. Yellow orthoclase from Madagascar and Germany may be slashed “en cabochon” to exhibit the cat’s eye effect.
Feldspars form in igneous and metamorphic rocks. Which sort is created depends upon the temperature it forms at, and just how it cools.

Properties

Chemical Composition: 

Potassium aluminium silicate

Crystal System / Forms: 

Monoclinic

Hardness: 

6

Specific Gravity: 

2.56

Lustre: 

Vitreous

Refractive Index / Birefringence: 

1.51-1.54 / 0.005

Cuts & Uses: 

Step cut