Moonstone

When a single feldspar crystal intergrows two different compositions (such as from the sodium potassium alkalai group and the sodium calcium plagioclase group), the brilliant iridescence of Moonstone may be produced.

• Period: 1
  • Garnets Feldspars
  • Hardness: 6-6.5
• Group: Group IA?

See also Matter, Gems, Na and Garnets Feldspars.

— Scotus - 05 Jan 2002