Webster's Revised Unabridged Dictionary · 1913

Elvan

Elvan , adjective

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.

Elvan , noun

The rock of an elvan vein, or the elvan vein itself; an elvan course.

Also: Elvanite