Sunstone is a variety of feldspar that has schiller, It commonly has a background color of orange/brown due to separate small Hematite (or Hematite and Ilmenite) (and sometimes also Goethite or Pyrite) crystals that give it it's flash and sparkle. Some Sunstone displays asterism (four-ray stars), which is known as Star Sunstone. Sunstone occasionally also displays a cat's eye effect.

Oregon Sunstone, also known as Heliolite, contains copper crystals instead of hematite, It is a transparent feldspar with colors ranging from water clear through pale yellow, soft pink, and blood red to (extremely rare) deep blue and green. 

Sunstone is found in Australia, Brazil, Canada, India, Norway, Russia, Madagascar, Tanzania, United States (Arkansas, New Jersey, New York, North Carolina, Oregon, Pennsylvania, South Carolina and Virginia). 

Sunstone is not heated, treated or altered.