We buy alexandrite rough.
Green to bluish-green in daylight, red to purplish-red under incandescent light. In rough, dull and greyish until wet.
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
Chrysoberyl habit — tabular, and very commonly as cyclic twins forming a pseudo-hexagonal 'trilling' with re-entrant notches. That trilling is one of the most recognisable shapes in all of gem rough.
orthorhombic
Green to bluish-green in daylight, red to purplish-red under incandescent light. In rough, dull and greyish until wet.
What it gets mistaken for
Alexandrite is commonly confused with colour-change garnet, colour-change sapphire and synthetic corundum sold as alexandrite. 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: colour-change chrysoberyl.
Where it comes from
We buy alexandrite from Brazil, Sri Lanka, Tanzania, Madagascar, India, Zimbabwe — and from anywhere else it turns up. A locality we have not listed is an omission, not a refusal.
Treatment
Generally none; some oiling of fissures.
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.