420 TABLE I. FOR DETERMINATION OF MINERALS. 



(luartz, 



Staurotide, 



Topaz, 



Spinel, 



Chrysoberyl, 

 Sapphire, 



Diamond, 



Hardness. 



rdh ; tough ; structure sometimes tesselated* 



Bl, bor fus dif, trp glass. Prim, 

 132. 7-0 VI ; mas ; G 2-6—2-8 ; colors various ; vit ; trp, 



op : Bl, soda fus ! trp glass, efferv. 

 174. 7-0—7-5 III ; stout prisms ; G 35— 38 ; bn, rdh-bn, bk ; vit, 



res ; strp, op. Prim. 

 200. 7-5 II ; cryst, seldom mas ; G 44 — 48 ; bn, r, yw, gy, gn 



w, some bright ; subad ; trp, trl : Bl, bor, clea 



glass. Prim ; gran limest. 

 194. 7-5—8-0 III ; prisms with basal cleavage ! mas, col ; G 3-4- 



3-6 ; pale y w, gn, b, w ; vit ; trl, strl : Bl, bor slowl 



trp glass. Prim. 

 160. 8-0 I; octahedrons, etc ; G 3.5 — 46 ; r, bh, gnh, yh, bn 



bk ; vit ; trp, strl, (some impure crystals soft): 



Bl, bor fus dif. Prim ; gran limest, etc. 

 199. 8-5 HI; cryst; G 3-5—3-8; bright gn, ywh, gyh; vit, 



trp, trl : Bl, bor fus dif I Prim. 

 158. 9-0 VI ; mas ; jn grains ; G 3-9 — 4-2 ; b, r, yw, bn, gyh-b. 



gy, w ; vit ; trp, trl : Bl, bor fus dif. Prim ; gran 



80. 10 





t Fusible 



Talc, 



143. 10—1-5 



Chlorite, 



145. 1-5 



Gypsum, 



112. 1-5—20 



Mica, 



191. 20—2-5 



Cryolite, 



132. 



Serpentine 



145. 20—3-5 



Chlorophyllite, 



162. 20—40 



Anglesite, 



281. 2-5—30 



Anhydrite, 



114. 2-5^-3-5 



I ; G 3-4—3-7 ; w, b, r, yw, gn, bn, gy, bk ; adaman- 

 tine ; trp ; 6trL # 



with more or less difficulty. 



Ill ; fol I mas ; G 27—2-9 ; light gn, gnh-w, gyh ; 



p'ly, unctuous ; laminae flexible, not elastic : Bl, 



infus, or fus dif!! Prim ,- gran limest. 

 Fol ; mas gran ; G 2-6 — 2-9 ; olive green; p'ly ; tvl 



decomp : Bl. fus dif! sometimes to a black glassy 



bead. Prim. 

 rV ; fol ! gran, stel ; G 2-2—2-4 ; w, gyh, bnh, rh, bk ; 



trp, trl; lam flexible, inelastic : Bl, fus dif; whi- 

 tens, exf, and becomes friable ; Strat. prim. vole. 

 Fol !! lam thin elastic, tough ; G 28—3 ; colors 



various, often bright; p'ly; trl, strl: Bl, fus dif I 



Prim, etc. 

 Mas, fol ; G 2-9 — 3 ; w ; vit, p'ly ; fusible in a candle. 



Prim. 

 Ill ; mas ; sometimes thin fol, fol brittle ; fib ; G 



2-4 — 2-6 ; dark or light gn, gnh-w, bh-w ; trl — op -, 



feel often greasy : Bl, fus dif!! 

 VI ; fol prisms ; fol brittle ; G 2-7— 2-8 ; dull green. 



gyh, bnh ; p'ly, vit : Bl, fus dif!! Prim with iolite, 

 HI; mas; lam; Gr 62 — 6-3; w, ywh, gyh; gnh, 



ad, vit, res ; trp, trl: Bl, fus !! decrep ; on char, 



lead globule. 

 Ill ; rectang cleav ! mas ; G 28 — 3 ; w, rh, bh, gyh 



p'ly, vit : Bl, fus dif; whitens ; not exf. 



* Thia tesselated variety is often quite soft, owing to impurities. 



