This page gathers the stones in our collection catalogued under the tradename AA. Tradenames of this kind — letter grades such as A, AA and AAA — are long-standing commercial descriptors used in the coloured stone trade to communicate where a gem sits within the usual range of its variety, principally in terms of colour saturation and overall appearance. They are conventions of the market rather than designations issued by any gemological laboratory, and their precise meaning can differ between houses, which is why we publish them alongside the individual characteristics of each stone.
At present the variety represented here is Tanzanite, the blue to violet gem form of zoisite. Tanzanite's colour is strongly influenced by orientation and by how a cutter balances face-up blue against the violet and burgundy directions present in the rough, so two stones sharing a tradename can still read quite differently in the hand.
When choosing between them, we suggest weighing colour and its behaviour under different lighting first, then clarity, then the quality of the cut — the proportions and polish that determine how brightly the stone returns light.
