Fluorescent Umber Peridot

Latin fluēre, to flow — adjectival suffix -escent. As a color modifier, fluorescent implies a saturated-and-UV-stimulated-glow quality, the bright color of fluorite-and-ZnS mineral-pigment fluorescent-lamp emission. Sits at the bright-and-cool end of the grid, parallel to phosphorescent and neon in usage.

Latin umbra, shadow. As a color modifier, umber implies a shadowed-and-Umbrian-earth-pigment quality, the visual register of Caravaggio-and-Rembrandt-umber hand-shadowed-and-Umbrian-earth-pigment Caravaggio-and-Rembrandt-and-Vermeer-Dutch-Golden-Age umbered-and-shadowed-and-deep-glazed surfaces under Caravaggio-and-Rembrandt-and-Vermeer chiaroscuro-and-tenebrist-and-glazed studio-window-light. Sits at the modifier-and-mood end of the grid, parallel to shade and gloom in usage.

The transparent green variety of olivine — the gem mined from Egyptian Zabargad Island since pharaonic times and now from arid mountain ranges in Pakistan, Arizona, and Vietnam. The color refers to a faceted peridot: a clean, slightly yellow-shifted green with the gem's signature internal warmth. Lighter than emerald, brighter than olivine in its rough state, with the unusual gem-trade quality of being one of the few minerals that occurs in only one color.