Gemology
Moonstone is part of the feldspar family and is mined mainly in Australia, India, Sri Lanka, and the United States. Moonstone has many color varieties such as White, Rainbow, Sand and Gray Moonstone. Its color and internal structure are determined by temperature and elements that affect the gemstone as it forms underground. The moon's internal structure allows it to reflect light in such a way that it looks like a streak of light, a glow of blue or rainbow colors. This optical effect is called adularescence. When measuring the hardness of a gemstone, you use the Mohs Hardness Scale. The scale varies from 1-10, where 10 is the hardest - here lies the diamond, which is the hardest gemstone. Moonstone is 6-6.5 on the Mohs Hardness Scale.