sassolin

from The Century Dictionary.

• noun Native boracic acid, H₃BO₃, occurring more or less pure in irregular six-sided laminæ belonging to the triclinic system, or as a crust, or in stalactitic forms composed of small scales.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Min.) Native boric acid, found in saline incrustations on the borders of hot springs near Sasso, in the territory of Florence.