DETERMINATION OF MINERALS. 393 



BH-2BERITE, p. 168. A cobalt sulphate. 

 REMINGTONITE, p. 168. A hydrous cobalt carbonate. 



3. COMPOUNDS OF MANGANESE. 



Give an amethystine globule in O.F. with borax. [The globule 

 looks black if too much of the manganese mineral is used, and with 

 a large excess may be opaque.] 



1. GIVES OFF CARBONIC ACID WHEN TREATED WITH DILUTE H CI ; 

 LUSTRE UNMETALLIC. 



RHODOCHROSITE, p. 191. H. =3 5-4-5; G. =3 4-37; rose-red. 



Also manganese-bearing varieties of calcite, dolomite, ankerite, side- 

 rite, all of which have the cleavage and general form of rhodochro- 

 site ; when containing a few per cent, of manganese they often turn 

 black on exposure. 



2. TREATED WITH H CI YIELDS CHLORINE FUMES. 



MANGANITE, p. 189. H.=4; G. =42-4-4; in oblong trimetric 

 prisms ; grayish-black, streak reddish-brown ; lustre submetallic ; 

 B. B. infusible ; vields water. 



PSILOMELANE,p. 189. H.=5-7 ; G. =3-7-4'7 ; amorphous ; black, 

 streak brownish-black ; submetallic ; B.B. infusible ; yields water. 

 Wad is similar, but often contains cobalt. 



PYROLUSITE, p. 188. H.=2-2 5; G.=4"82 ; in stoutish trimetric 

 crystals ; metallic ; dark steel-gray, streak black or bluish-black ; 

 B.B. infusible ; yields no water. 



BRAUNITE and' HAUSMANNITE (p. 189) are other anhydrous 

 manganese oxides. 



FRANKLINITE, p. 179. H. =5-5-6 5; G. =5-5-1 ; in octahedrons 

 and massive ; iron-black, streak dark reddish brown; B.B. infusi- 

 ble ; but little chlorine with H CI. 



3. C0 2 OR CI NOT GIVEN OFF WHEN TREATED WITH H CI ; 

 ANHYDROUS. 



RHODONITE, p. 247. H.=55-6-5; G.=34-3 68; rose-red; B.B. 



fllSGS G£LSllv 



TRIPLITE," p. 191. H.=55; G. =34-3-8, • brown to black; B.B. 



fuses very easilv, globule magnetic ; sol. in HC1. 

 HELVITE, p. 256. H.=6-6 5; G. =3 1-33; in yellowish tetrahe- 



hedrons ; B. B. fuses easily. 

 SPESSARTITE (Manganesian Garnet), p. 258. H. =65-7 ; G =37- 



4*4 ; in dodecahedrons and trapezohedrons ; red, brownish-red ; 



B.B. fuses easily. 

 TEPHROITE, p. 256. H. =5-5-6; G. =4-412; reddish to brown 



and gray ; B.B. fuses not very easily ; gelat. in H CI. 

 Knebelite, p. 256, is related, and also gelatinizes. 



