basanite

Basanite, bas′an-īt, n. a kind of quartz serviceable for testing the purity of the precious metals by the marks made.

In the fourth, again, he was seen converting the ill-advised Battus into that stone that is called basanite; and in the fifth and last was his slaying, so cunningly achieved, of the many-eyed Argus.

Let him be an old shepherd seated, showing with the forefinger of the right arm the place where the cattle were hidden, and leaning with the left arm on a stick or rod, the herdsman's staff; and from the waist downwards he must be of black stone of the colour of basanite, into which stone he was converted.

Or is he a kind of basanite for bunches, and do they come out on us at the sight of him?

The flows from Kibo include nepheline and leucite basanite lavas rich in soda felspars.