12 



APPENDIX. 



247 D. Nigrescite. F. Eornstein, ZS. G. Ges., 1867, 342. 



Amorphous. Fracture uneven and splintery. BL=2. G. =2 '845. Color, ' when fresh, 

 apple-green ; on exposure becomes gray to black ; opaque and earthy, and, on drying, as light 

 as wad. Loses 16 '5 per cent, hygroscopic water. 



Analysis : 



Si Ad Fe Mn Mg Ca fi[ 



| 52-29 5-14 15-71 023 18-11 2-59 6-29=100-36 



Perhaps the product of the alteration of a magnesia-iron augite or amphibole. 

 Found in rounded masses in basalt, at Dietesheim, in the valley of the Maine. 



Orileyite. D. Waldie, Proc. Asiatic Society, Bengal, p. 279. September, 1870. 

 Massive. H. =5'5. G. =7'34 — 7 "42. Color steel-gray, on fresh fracture with purplish 

 tint. Lustre metallic. Streak dark-gray. Analysis, D. Waldie (1. c.) : 



As Sb Cu Fe X Insol. 



38-45 0-54 12-13 42-12 619 0'12=99-55 



X, oxydized matters soluble in dilute muriatic acid = Cu 1 - 21, Fe 1*97, Pb 1 - S9, lis 1"12= 

 6-19. B. B. in the closed tube yields no arsenic. Soluble in nitric acid. 

 From Burrnah, but exact locality not known. Needs further investigation. 



Osbornite. — This name has been given by Maskelyne to small gold-yellow octahedrons 

 occurring in augite in a meteorite from Busti, India. It is supposed to be an oxysulphid of 

 titanium and calcium. 



Phosphorchromite. See Laxmannite. 



374. PlumbaUopJiane. A name given by Bombicci to a plumbiferous allophane from 

 Monte Vecchio in Sardinia. Occurs in small stalactitic cylinders, rough and opaque on the 

 surf ace, but interiorly glassy. Color grayish -yellow with a white streak. H. =25. G. =19. 

 Analysis gave Si 23 8, P" 26, Si 32-9. Fe 0"5, Ca 2'4, H 35 2, Pb, Mg and alkalies 2-5=999 

 (Atti della Sc. Ital. di Sc. Nat. xi., in Jahrb. Min. 1868, p. 750. 



40 C. Polyargyrite. F. Sandberger, Jahrb. Min., 1869, 311. T. Petersen, Pogg. 

 Ann., cxxxvii. 386. 1869. 



Isometric. Observed planes 1 O i, m-m. Cleavage cubic. H. =2 "5. G. =6-974. Lustre 

 metallic. Color iron-black to dark blackish-gray. Streak black to blackish-gray. Malleable, 

 flattening more under the hammer than argentite. 



Composition: 12 Ag S + Sb 2 S,=Ag. 78-16, Sb 7 "37, S 14-47=100'00. 



Analysis, Petersen (1. c.) : 



S Sb Ag Pb Fe Zn 



§ 14-78 6-98 76-70 tr. 0-36 0-27*=99'09 



* Corrected. 



B. B. on charcoal fuses easily to a black globule, giving off antimony fumes, and yielding 

 a brittle globule of silver. Soluble with difficulty in nitric acid with separation of sulphur. 

 Fuming acid dissolves it readdy with separation of antimonate of sdver. - 



Occurs at Wolfach in Baden. 



The mineral is between argentite and pyrargrite in composition. If homogenous it would 

 be classified chemically near polybasite ; but its isometric form, and the fact that in another 

 analysis Petersen found 78 "85 Ag, suggests that it may possibly be a mixture. 



624. Pucherite. A. Frenzel, J. pr. Chem., LT. iv. 227, 301. >8ji- 



Orthorhombic. Observed planes i, O, 1-%, m-u. Cleavage basal. H. =4. G.=5-91. 



Lustre vitreous adamantine. Color reddish-brown. Streak yellow. Translucent to opaque. 



Composition : Bi V=Bi 71-67 V 28-33=100. Analyses, 1. 2. Frenzei (1. c.) : 



V Bi 



1. 27-31 73-39=100-70 



2. 27-07 72-93=100 — 



In the closed tube decrepitates. B. B. on charcoal fuses and gives a coating of bismuth- 

 oxyd, with soda vields a globule of metallic bismuth. With salt of phosphorus a chrome- 

 green bead in R. F. becoming light yellow in O. F. (vanadium). Soluble in muriatic acid 

 With evolution of chlorine to a deep-red solution, which on dilution becomes green and 

 deposits a yellow basic chlorid. 



Named pucherite from the locality, the Pucher Mine, Schneeberg, Saxony. Found asso- 

 ciated with bismite and asbolite. 



