Heavy Spark 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.

Old English spearca, small-ember. As a color modifier, spark implies a small-bright-and-flying-ember quality, the visual register of blacksmith-anvil-and-bonfire-spark hand-small-bright-and-flying-ember blacksmith-anvil-and-bonfire-and-flint-strike sparked-and-small-bright-and-flying surfaces under blacksmith-anvil-and-bonfire-and-flint-strike orange-glow-and-iron-and-flint forge-and-hearth-light. Sits at the modifier-and-mood end of the grid, parallel to flash and flare 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.