One of the Munsteiners patented the Context and Spirit Sun cuts for
diamond about ten years ago, or so. When I first saw them, I
giggled, because I used to use those cuts to teach beginners how to
facet color. They are quite simple and have been around and cut by
colored stone faceters for a very long time. However, they are
patented for diamond and cannot be cut in diamond without permission
from the patent holder. There is no restriction for cutting them in
other than diamond, but the names "Context" and "Spirit Sun" cannot
be freely used for color. Spirit Sun has been commonly called the
"Spinning Wheel" or "Wagon Wheel" cut in publications for colored
stone cutters, while the "Context" cut, is a simple four-facet crown
and four-facet pavilion. The pavilion is cut on the correct pavilion
angles for the material, but the crown is cut to very low angles.
The result is an optical illusion in the stone that is very
striking, quite unlike the usual brilliance, and very pretty. It
gets a little "lost" in high RI materials, IMO. Interestingly, they
were originally designed for low refractive index materials like
quartz and beryl, and Munsteiner adapted them to diamond and
patented the design (for diamond). The idea of creating cuts whose
beauty lies in internal optical illusions rather than "brilliance"
is one that has not been fully explored, although they are quite
easy to perform. I have a whole series of cuts that work on that
principle. Many of my jewelry store customers like these for
earrings, as they are strikingly different, and different SELLS. For
me, it's a way to offer something out of the ordinary, yet not
expensive. I like them in paler amethyst or nice yellow-orange
citrine, but my real favorite is cut in a color-change synthetic
that goes from light blue-green to pink to purple. It's just fun!!
Sorry, I got carried away!!