A Large Baroque Tridacna Gigas (Giant Clam) Pearl
This giant clam pearl was noteworthy for its size and interesting colouration, and its pronounced banding when viewed with transmitted light.
Aquamarine with Unusually Strong Dichroism
This aquamarine's most striking feature was its unusually strong dichroism, displaying very deep blue and pale bluish green colours.
Water Immersion Reveals Dye in Fire Opal
A simple test easily detected dye treatment in fire opal.