We buy iolite rough.

Violet-blue, and EXTREMELY pleochroic — violet-blue, near-colourless and yellow-grey from three directions.

How to tell if this is what you have

What it gets mistaken for

Iolite is commonly confused with sapphire, tanzanite and amethyst. That cuts both ways — people sell it as something less than it is at least as often as the reverse. If you are not certain what you have, send photographs anyway and say you are not sure. We would far rather look at something and tell you it is not what you hoped than have you throw it back on the heap.

Also traded as: cordierite.

Where it comes from

We buy iolite from Sri Lanka, India, Madagascar, Tanzania, Brazil — and from anywhere else it turns up. A locality we have not listed is an omission, not a refusal.

Treatment

None generally.

Tell us what has been done to it, if you know. We buy treated material where the treatment is a normal part of the trade — what we cannot do is find out afterwards, because then it is a problem for whoever owns the stone next and eventually that is us.

How to photograph it

Daylight, on a plain white surface, and wet and dry both. Rough seen dry is frosted and reads far paler and greyer than the same stone wet — a parcel photographed dry has cost its owner money more times than we can count. Put a coin or a ruler in the frame for scale. The full guide is here.

← every stone we buy