What determines a gemstone's price?

Where a stone was mined tells much of its story. A Kashmir sapphire, a Burmese ruby, a Colombian emerald — each origin carries a reputation earned over centuries. The same species from a lesser-known source (a Thai ruby, a Zambian emerald) can be beautiful, but it rarely commands the same price.

Colour is judged on hue, saturation and tone together. The legendary "pigeon-blood" red of a fine ruby is the benchmark its peers are measured against. What matters is that the colour is natural — not artificially induced — and that it sits in the narrow band the eye reads as truly vivid.

Clarity standards differ by gem. Emeralds are expected to carry inclusions — their internal "jardin" is part of their character — so a genuinely clean emerald is far rarer than a clean ruby. Clarity is always read against what is normal for that particular stone.

Weight is measured in carats, but price-per-carat does not rise in a straight line — it jumps. A fine two-carat stone is not twice a one-carat; it can be several times the price, because large, clean, well-coloured stones are exponentially scarcer.

Most coloured stones on the market are treated — heated, oiled, or diffused — to improve colour or clarity. An untreated, fully natural stone commands a real premium. Whatever has been done to a stone, it is disclosed in full on its certificate. No surprises.