VAUQUELISITE. 559 the Ural, in veins of quartz in granite, at Totschilnaja Gora near Mursinsk, and at Bertewaja Gora near Nischne-Tagilsk ; with quartz in a vein in talcose slate at Congonhas do Campo in the province of Minas Geraes in the Brazils. 393. PIKENICITE.—Melanochroite ; Dufrenoy. Melano- chroit; Mohs. Phonikoehroit; Ilausmann. Phonicit; Hai- dinger. Cleavage in one direction perfect. Translucent on the edges. Lustre resinous, adamantine on the cleavage. Bed. Streak brick-red. Slightly brittle. 11 = 3'0...3'5. a = 675. Before the blowpipe on charcoal melts into a dark mass which crystallizes on cooling. In the inner flame the lead is reduced. Imparts a green colour to borax and salt of phos phorus. Partially soluble in hydrochloric acid, leaving a residue of chloride of lead. After prolonged exposure to heat the solution becomes green. 1 Pb 3 Cr s , chromic acid 2370, oxide of lead 76-30. Analysis by Hermann :— Chromic acid 23 - 31 Oxide of lead 76 69 Is found in small, nearly right-angled, tabular crystals and massive, in veins of quartz with galena and lohmannite, at Bere- sowsk in the Ural. 394. VAUQUELINITE.—Vauquelinito; Phillips, Beudant. Hemiprismatischer Melanochlor-Malachit; Mohs. Vauque- bnit; Hausmann, llaidinger. Obliquo. e ooi, a 100 twin-face, e 101, v ill. FIG. 660. Combinations, cv, eve. Twins. Twin-faco a. co = 45° 3o'. The faces c smooth and bright; the other faces slightly curved. Cleavage not observable. Fracture flat conclioidal...uneven. Slightly translucent...opaque. Lustre on surfaces of fracture waxy ; on the faces of the crystals adamantine. Siskin-green, olive-green, blackish-green, brown. Streak siskin-green, fre quently inclining to brown. H = 2-6...3 - 0. g = 6-6...5-8. B b 4