feldspar gemstone properties
Orthoclase Gemstone Information. About Orthoclase-History and Introduction. Orthoclase is a rare gemstone that belongs to the feldspar group, which also includes moonstone, amazonite, spectrolite and labradorite. Therefore, orthoclase is sometimes also called K-spar.Orthoclase gemstones are typically champagne yellow, golden yellow or greenish, though they can be other colours.rthoclase Gemstone Information. About Orthoclase-History and Introduction. Orthoclase is a rare gemstone that belongs to the feldspar group, which also includes moonstone, amazonite, spectrolite and labradorite. Therefore, orthoclase is sometimes also called K-spar.