elvan
  淡英斑岩
  Elv·an, Elv·an·ite, n. The rock of an elvan vein, or the elvan vein itself; an elvan course.
  ◄ ►
  Elv·an a.
  1. Pertaining to elves; elvish.
  2. Mining Of or pertaining to certain veins of feldspathic or porphyritic rock crossing metalliferous veins in the mining districts of Cornwall; as, an elvan course.
  ◄ ►