Moonstone is a part of the feldspar family and is mainly extracted in Australia, India, Sri Lanka, and The United States. Moonstone has many colour varieties such as White, Rainbow, Sand, and Grey Moonstone. Its colour and the inner structure are determined by temperature and elements that affect the gemstone when it formed underground. The Moonstone’s inner structure allows it to reflect light in a manner that makes it appear as a stripe of light, a glow of blue or rainbow colours. This optical effect is called adularescence. When measuring a gemstone’s hardness, Moh’s Hardness Scale is used. The scale goes from 1-10, where 10 is the hardest – here you would find the diamond, which is the hardest gemstone. Moonstone is a 6-6.5 on Moh’s Hardness Scale.