The Black Hole

Fluorite is calcium fluoride, a soft and perfectly cleavable mineral that rewards the cutter with unusually pure colour when the rough survives. A small fraction of material shows a genuine colour change between daylight and incandescent light, driven by rare-earth trace elements rather than by treatment.

The Black Hole is a 1391.46 ct cushion, cut in a combined brilliant and step pattern, and documented in an independent laboratory report as natural colour-change fluorite with no detected treatments: blue in daylight, purple under tungsten.