Natural Ethiopian Opal, Freeform Shield Cut

Normally I cut lab gems, but I thought it would be fun to try cutting some natural Ethiopian opal for a change.  This is reverse hydrophane opal, which means it has better color when it's dried out (in fact, the stones come out of the ground so dry that they'll stick to your skin as they try to suck the water out of your body).

The size is 16.6×11.2mm and it weighs in at 5.3 ct.