Although Orthoclase is one of the more common minerals found on Earth, gem-quality material is incredibly rare. A transparent to translucent member of the Feldspar family, Orthoclase is a stunning gemstone that is available in several colours. Because the gem has fairly unique planes of fracture which are at right angles to one another, its name is derived from the Greek word for “straight fracture”.
Although often found colourless, Orthoclase can also be discovered in a wonderful light green colour which to the naked eye can make it first appear similar to a Green Amethyst. Yellow coloured ortholase similar to Lemon Quartz has been mined in Burma and Madagascar.
Labradorite, with its beautiful labradoresence, is the greyish form of Orthoclase and Oligoclase is a yellow to orange member of the family. If you are struggling to keep up with this, it’s a bit like the Beryl family, where the family name “Beryl” is used as a name in its own right for “Yellow Beryl”, yet Aquamarine, Emerald and Morganite all have their own names, even though they are all Beryls. Moonstone is sometimes incorrectly labelled as an Orthoclase, however strictly speaking it is formed by a crossbreed of Orthoclase and Albite, albeit (sorry about the pun) the majority is made up of the former.
