Fluorescent Welsh 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.

Old English Wælisc, of-Wales. As a color modifier, welsh implies a Cymric-and-slate quality, the visual register of Welsh-Cymric hand-built slate-and-stone-and-Welsh-wool valley-and-mountain hand-spun-and-hand-quarried surfaces under Welsh-Cymric Snowdonia-and-Brecon-Beacons valley light. Sits at the modifier-and-cultural end of the grid, parallel to celtic and scot 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.