- A stone’s rarity depends on its origin, colour, and the number of known specimens.
- Some gemstones are far rarer, and sometimes more expensive per carat, than diamonds.
- Colour, clarity, and origin determine the value of exceptional stones.
Diamonds dominate the collective imagination, but they are not the rarest stone. Several gemstones, extracted in minuscule quantities from only a few deposits, reach astronomical prices among collectors and high jewellery houses.
Gemstones Rarer Than Diamonds
Some stones count only a handful of gem-quality specimens worldwide. Painite, long considered the rarest mineral, or grandidierite, with its luminous blue-green hue, are among the most coveted. Tanzanite, extracted from a single deposit in Tanzania, or musgravite exemplify this extreme geographical rarity that causes prices to soar.
The Weight of Colour
For coloured stones, hue often takes precedence over cut. The “pigeon’s blood” ruby, the deep green Colombian emerald, or the Padparadscha sapphire, a subtle blend of pink and orange, achieve staggering values per carat. A pure, vibrant, and saturated shade, without treatment, multiplies a gem’s value compared to a duller stone.
What Determines Value
Colour, clarity, cut, and origin form the equation of rarity. A prestigious provenance, such as a Burmese ruby or a Colombian emerald, adds a sought-after premium. The absence of treatment, attested by an independent laboratory certificate, has become crucial. These exceptional stones, discreet yet invaluable, concentrate immense value within a few grammes.
