DIAMOND KNOWLEDGE

Diamonds, the way the trade sees them.

Eight years grading with the GIA, more stones than I can count. This is only about diamonds — how to weigh the 4Cs, how to read a certificate, where not to overpay. Nothing to sell you; only to help you choose.

DIAMOND TYPESThree stones, hard to tell by eye.

Diamond 鑽石

Lab-Grown Diamond 培育鑽石

Moissanite 莫桑石

FANCY-COLOUR SPECTRUMDiamonds aren't only white.

These are from my own reference set — each the best sample I have of its colour. A fancy diamond's value order is nothing like a white one's: colour intensity comes first, and clarity second.

Colourless白鑽Colourless (D–Z scale) — the classic diamond; the more colourless, the dearer.

Fancy Pink粉紅鑽Colour from lattice distortion; the Argyle mine is closed, and supply keeps shrinking.

Fancy Blue藍鑽Coloured by boron, and one of the few diamonds that conduct electricity.

Fancy Yellow黃鑽Coloured by nitrogen, the most common and most accessible fancy diamond.

Fancy Green綠鑽Natural radiation greens the surface, usually only a thin skin.

Fancy Brown啡鑽Champagne to cognac — the most common and affordable diamond colour.

Fancy Red紅鑽Only a few dozen known worldwide — the rarest fancy diamond.

Looking for coloured and semi-precious stones? See the Gem Library. 看中文版 →