We buy cuprian (paraíba-type) tourmaline rough.
Copper-bearing: the neon blue-green is unmistakable when clean, but much rough is a dull grey-violet that only comes alive on heating.
Send photographs of what you have Tell us the weight and where it is from. There is no obligation.How to tell if this is what you have
Tourmaline habit — striated prisms, rounded-triangular cross-section. Brazilian material is often heavily fractured and small.
trigonal
Copper-bearing: the neon blue-green is unmistakable when clean, but much rough is a dull grey-violet that only comes alive on heating.
What it gets mistaken for
Cuprian (Paraíba-type) tourmaline is commonly confused with ordinary indicolite, apatite and chrysocolla-included quartz. 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: Paraíba, neon tourmaline.
Where it comes from
We buy cuprian (paraíba-type) tourmaline from Brazil, Nigeria, Mozambique — and from anywhere else it turns up. A locality we have not listed is an omission, not a refusal.
Treatment
Routinely heated, which is expected and disclosed rather than a defect.
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.
Send photographs of what you have Tell us the weight and where it is from. There is no obligation.