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The Pennyweight

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Diamonds & Stones

What a grading report says, which laboratory said it, and whether a stone is natural, lab-grown, moissanite or treated. Four disclosures that change the price by an order of magnitude — and that several catalogues sell side by side.

Where to start

Comparisons

Glossary terms

The 4 Cs
Carat, colour, clarity, cut — what a diamond grading report records.
Points
One hundredth of a carat. A 25-point stone is 0.25 ct.
Table
The large flat facet on top of a cut stone — the window you look through.
Girdle
The narrow band around a stone’s widest point, where a setting grips it.
Culet
The point or small facet at the bottom of a brilliant-cut stone.
Lab-Grown Diamond
A real diamond made in a reactor rather than mined — and disclosed as such.
Moissanite
Silicon carbide — a different material from diamond, with different optics.
Treated Stone
A stone altered after cutting — clarity-enhanced, irradiated or HPHT-processed.

The short list

Three entries from the ledger — the full ranking lives on the best-of pages.

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