SUNSTONE:  Also known as heliolite, ( a semi-to-transparent feldspar) with colors that can range from clear through shades of lighter yellows, bronzy pinks, greens, and peachy reds.  Some, although extremely rare, are blood red and dark blue. The color appears to vary depending on the small amounts of copper found in this very unique gemstone.

Thus, the color of the gemstone will depend on both the amount and the size of individual particles of copper present in the stone.  When viewed in just the right direction or angle, a pinkish to reddish metallic shimmer flashes from within the stone. This called the "schiller" effect.  This "schiller" is very much preferred, and certainly sets this gemstone apart from most others.