The group
Spodumene grows large. Crystals of several metres are known from pegmatites, and faceted kunzite of a hundred carats is not remarkable — which is unusual among coloured gems and keeps the price per carat modest even at large sizes.
It is also one of the hardest materials to cut. Perfect cleavage in two directions means the stone can split during faceting, during setting, or later if knocked. Cutters charge more for it, and a good setter will insist on a protective mounting.
The colour problem is worse. Kunzite fades. Prolonged exposure to strong light, and particularly to sunlight, drains the pink. Much of the material on the market has also been irradiated to deepen the colour in the first place, and irradiated colour fades faster. It is sometimes called an evening stone for exactly this reason.
Genuine hiddenite — green spodumene coloured by chromium, from North Carolina — is rare and often confused with ordinary green spodumene, which is coloured by iron and is a different and much cheaper thing.
Every spodumene compared
The whole group side by side. Where the constants overlap, the species cannot be named from a refractometer alone — which is exactly why the trade names mislead.
| Variety | Species | Colour | Mohs | RI | SG | Guide price |
|---|---|---|---|---|---|---|
| Hiddenite | Spodumene | green | 6.5–7 | 1.660–1.676 | 3.15–3.21 | $50–1,000/ct |
| Kunzite | Spodumene | pink | 6.5–7 | 1.660–1.676 | 3.15–3.21 | $5–120/ct |
| Spodumene | Pyroxene group | pink | 6.5–7 | 1.657–1.681 | 3.15–3.21 | 10–80 USD/ct faceted; fine large kunzite 30–120 USD/ct |
| Triphane | Spodumene (pyroxene group) | yellow | 6.5–7 | 1.660–1.676 | 3.15–3.21 | $10–80/ct |
Questions
Does kunzite fade?
Yes. Kunzite loses colour with prolonged exposure to strong light, and irradiated material fades faster than natural. Store it in the dark and do not wear it in strong sun if you want the colour to last.
Is kunzite hard to set?
Yes. Perfect cleavage in two directions means it can split during setting or if struck later. Use a jeweller who has worked with it, and choose a protective mounting.
What is the difference between hiddenite and green spodumene?
Hiddenite proper is coloured by chromium and is rare and valuable. Ordinary green spodumene is coloured by iron and is common and cheap. The names are used interchangeably by sellers, and they should not be.
Looking for spodumene?
Tell us which variety, what size and what it is for. We source it, photograph it and quote it, with the locality named.
Ask about spodumene