This page gathers stones in our collection carried under the trade designation AAA+. In the coloured stone trade, letter grades of this kind are a shorthand for the uppermost tier of colour within a given variety — depth and evenness of hue, saturation that holds across the face of the stone, and an absence of dulling grey or brown modifiers. It is a descriptive vocabulary rather than a universal standard, so the stone itself always remains the final authority.
The variety represented here is Tanzanite, the blue-violet gem form of zoisite. Tanzanite is strongly pleochroic, showing blue along one crystal direction and violet to burgundy along another, which means the cutter's choice of orientation largely determines whether a finished gem faces predominantly blue or predominantly violet. Both readings are legitimate; the preference is yours.
When comparing stones on this page, weigh colour first: view each gem in daylight and under warm artificial light, since tanzanite's balance of blue and violet shifts between the two. Then consider how saturation relates to size, the precision of the cut and its effect on light return, and the clarity you require for your intended setting.
