SLATY MERCURIAL HEPATIC-ORE. 31 It occurs massive. The lustre of the principal fracture is shining; that of the cross fracture is glimmering, and both have a semi- inetallic lustre. The principal fracture is curved and thick slaty ; the cross fracture is even. It occurs in globular, and concentric lamellar concre tions. The fragments are slaty. It is uncommonly easily Irangible. In other characters, it agrees with the preceding sub species. Geofrnostic Situation. O This mineral occurs in considerable masses in slate-clay and bituminous-shale. It is sometimes intermixed with einnabar and iron-pyrites ; and veins ol native mercury and of cinnabar occasionally traverse it. Both species oc cur together. Geographic Situation. It occurs most abundantly in Idria : it is also met with at Almaden in Spain, Nertsclunsk in Siberia, and in Deux Fonts. Observations. 1. The variety in globular and concentric lamellar concretions is named Corallencrz. 2. When exposed for some time to the air, it acquires a liver-brown tint of colour : hence the name Hepatic or Liver-cre given to it. 5. Cinnabar.