Heavy Arbor Tanzanite

Old English hefig, weighty — cognate with heave. Used as a color modifier since at least the seventeenth century to indicate weight in saturation as much as value: heavy with pigment, heavy-bodied. In the engine's adjective grid, heavy sits alongside deep and plush in the dark-and-saturated quadrant. Closer to a fabric description than a pure value word.

Latin arbor, tree-or-trunk. As a color modifier, arbor implies a Latin-tree-and-vine-arbor quality, the visual register of Pliny-Natural-History-and-Roman-villa-arbor hand-Latin-tree-and-vine-arbor Pliny-Natural-History-and-Roman-villa-arbor-and-pergola arbor-and-Latin-tree-and-vine-arbor surfaces under Pliny-Natural-History-and-Roman-villa-arbor-and-pergola Pompeii-and-Tuscan-pergola-and-grape-arbor leafy-shade-light. Sits at the modifier-and-Latin end of the grid, parallel to via and domus in usage.

A blue-violet variety of zoisite — discovered in 1967 in a single small area of northern Tanzania near Mount Kilimanjaro and marketed by Tiffany & Co. shortly after. The color refers to a faceted tanzanite cut to maximize its strong pleochroism: a saturated, slightly violet-shifted deep blue-purple with the gem's signature internal life. Cooler than amethyst, warmer than iolite, with the gem-trade specificity of a stone that occurs in exactly one place on Earth.