Acid Libra Peridot

Latin acidus, sour — sharing root with English acrid and acerbic. As a color modifier, acid implies a saturated-and-citric-and-zingy quality, the bright color of lemon-and-lime citrus-fruit-flesh and acid-yellow fluorescent-pigment surfaces. Sits at the bright-and-cool end of the grid, parallel to acidic and electric in usage.

Latin libra, scales-of-the-zodiac. As a color modifier, libra implies a scales-and-air-sign-and-Venus-ruled-cardinal-air quality, the visual register of Roman-Libra-and-scales-of-justice hand-scales-and-air-sign-and-Venus-ruled-cardinal-air Roman-Libra-and-scales-of-justice-and-Themis-Astraea libra-and-scales-and-air-sign surfaces under Roman-Libra-and-scales-of-justice-and-Themis-Astraea autumn-equinox-and-September-and-October cardinal-air-sign-light. Sits at the modifier-and-zodiac end of the grid, parallel to virgo and scorpio 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.