Peach Moonstone

Peach moonstone is the familiar moonstone, just in a warm shade. According to GIA, moonstone is a variety of orthoclase, a mineral of the feldspar group, and GIA lists peach among its colors. The photo shows two polished oval stones in a peachy brown shade, and on one of them you can see faint parallel stripes.

Moonstone's glow is called adularescence. According to GIA, as the stone forms, orthoclase and another mineral, albite, separate into very thin layers, and light is scattered between them. According to Geology.com, in stones with a colored body the glow is usually white to silvery, and the rare "blue flash" appears mostly in colorless stones. So do not look for electric blue in a peach stone. It does something quieter.

The word adularescence has an address too: according to Geology.com, fine moonstone was mined in the Swiss Alps near the St. Gotthard Pass, once called Mt. Adular, and it was named adularia. Today the most important source is Sri Lanka, and a lot of moonstone also comes from India, Brazil and Myanmar. According to Geology.com, there are no large mechanized moonstone mines, and most mining is done by hand, in stream gravels.

Now for the warning: according to Geology.com, moonstone has two directions of perfect cleavage, and one sharp knock can split it in two. The site even shows a photo of a moonstone ring that this happened to. So earrings and pendants? Great. A ring for gardening? Less so.

For the stories about the Romans, who thought moonstone was made of solidified moonbeams, and about Florida, see the grey moonstone page.