Feldspars come in a variety of colors, transparencies, and
adluresence. Moonstone is generally the translucent form of feldspar
which had an adlurescence which resembles a half moon. It comes in
white, peach, orange, green, and many off color combinations of these
colors. It is natural.
The opaque varieties of feldspar come in many varieties also. The
ones which have multiple peacock colors are often called Labradorite
or Spectrolite. Labradorite comes from Labrador, and Spectrolite
comes from Madagascar or Finland (normally). It is natural.
There are other varieties in massive formations that are used for
monuments, and decorative designs. Gerry Galarneau