Pictured here is a 4.64 carat ametrine that is 10.3 mm wide and has concave facets on the pavilion side.
The rough material for this stone is Bolivian origin obtained from New Era / Steve Ulatowski during the Tucson Gem shows last February. Before it was cut, it was easy to see that the amethyst / purple was isolated on less than half of the stone, but now the colors reflect and mix.
This 5.47 carat ametrine is half the purple amethyst color and half the orange citrine color, but it all gets mixed up in this sort of cut. The camera does a better job of “seeing” the two colors than my eye in most cases.
To see this for yourself, come by the Orcutt Mineral Society show this weekend being held Friday through Sunday at the Nipomo High School. It will be on display by the faceting demonstration along with a selection of other faceted gems.
Three garnets and the rest of the dozen are quartz varieties — citrine and amethyst. A few of those have concave facets.
