How to Match a Pair of Colored Gemstones

Matching a pair of coloured stones.

I remember sitting in a cramped grading lab in London, the air smelling of ozone and stale coffee, staring through a loupe at two sapphires that were supposedly “identical twins.” On paper, they were a match; in reality, one had a saturation like a deep, midnight ocean and the other looked like a faded, sun-bleached … Read more