This specimen, which I've been told is rather large for the locality, is really attractive both under UV and in daylight. It fluoresces a rich, vibrant saturated red under longwave. It's not quite apparent on the pictures due to the angle the specimen was photographed in, but the specimen is actually twinned.
Provenance: An Phú, Lục Yên District, Yên Bái Province, Vietnam
13 mm X 11 mm x 7 mm
Shown below under longwave UV and visible light.
