Moonstone is a variety of which mineral?

Moonstone is recognized as a variety of feldspar, which is a group of tectosilicate minerals that are among the most abundant in the Earth's crust. Specifically, moonstone is typically a potassium aluminosilicate, often referred to as orthoclase or sanidine, which contributes to its unique optical phenomena known as adularescence. This phenomenon gives moonstone its characteristic shimmering glow that appears to rise to the surface, inspiring its name.

Understanding the mineral classification is essential in gemology since it helps in identifying the gem's properties, origins, and valuation. The attributes of moonstone, including its range of colors and transparency, are directly linked to its feldspar composition. Thus, recognizing moonstone as a variety of feldspar is fundamental to gemological studies.