Basanite
[bæsәnait]
Definition
(n.) Lydian stone, or black jasper, a variety of siliceous or flinty slate, of a grayish or bluish black color. It is employed to test the purity of gold, the amount of alloy being indicated by the color left on the stone when rubbed by the metal.
Inputed by Dan
Definition
n. a kind of quartz serviceable for testing the purity of the precious metals by the marks made.
Editor: Luke