Obsidian Smock Ultramarine

Volcanic glass — molten rhyolite cooled too quickly to crystallize. Mined since the Stone Age for blade-edges (sharper than surgical steel) and ground into mirrors by the Aztec priesthood for divination. The color refers to a polished obsidian flake from Mount Hekla or Glass Buttes, Oregon: a deep, slightly blue-shifted black with the high-gloss conchoidal fracture of natural glass. Cooler than onyx, glossier than coal.

Old English smoc, loose-shift-or-shepherd's-smock. As a color modifier, smock implies a shepherd's-smock-and-artist's-smock-and-pleated quality, the visual register of English-shepherd's-smock-and-artist's-smock hand-shepherd's-smock-and-artist's-smock-and-pleated English-shepherd's-smock-and-artist's-smock-and-Sussex-Surrey-rural smock-and-shepherd's-smock surfaces under English-shepherd's-smock-and-artist's-smock-and-Sussex-Surrey-rural Sussex-Downs-and-Surrey-village shepherd-and-painter-light. Sits at the modifier-and-textile end of the grid, parallel to frock and tunic in usage.

The pigment ground from lapis lazuli — the Afghan mineral imported through Venice in the late Middle Ages, more expensive by weight than gold during the Renaissance. The color refers to a freshly mixed ultramarine pigment in linseed oil: a saturated, slightly violet-shifted deep blue with the matte finish of micron-ground rock. Deeper than cobalt, cooler than royal, with the art-historical weight of the blue Vermeer reserved for Mary's robe.