398 DETERMINATION OF MINERALS. 
ARAGONITE, p. 218. H.=3'5-4; G.=2.94; trimetric, cleavage im- 
perfect ; otherwise like calcite. 
DOLOMITE, p. 219. H.—3°5-4 ; G.=2-8-2°9 ; rhombohedral, RAR. 
=106° 15’; colors various ; effervesces but slightly with cold HCl, 
unless finely pulverized ; anhydrous. S 
MAGNESITE, p. 207. H.=—3 5-4°5 ;s G.=—8-3'1 ; rhombohedral, RAR 
=107° 29'; white, ywh, gyh; effervesces but slightly with cold 
HCl; anhydrous. 
HYDROMAGNESITE, p. 207. H.=1-3'5 ; G.=2:14-2:18 ; hydrous. 
@ - e 
B. INFUSIBLE ; BECOME MAGNETIC AND NOT ALKALINE AFTER 
IGNITION. 
SIDERITHS, p. 185. H.=35-4:5; G.—3:'7-3'°9 ; rhombohedral, &: & 
=107° ; cleavage as in calcite ; becomes brown on exposure, chang- 
ing to limonite, 
ANKERITE, p. 186. H.=3°5-4; G.=—2°9-3:1; RA R=106° 7; be- 
comes brown on exposure. 
Some kinds of calcite and dolomite contain iron enough to become 
magnetic on ignition. 
C. INFUSIBLE ; B.B. ON COAL WITH SODA, COATING OF ZINC OXIDE.. 
SMITHSONITE, p. 156. H.=5; G.=4-45; rhombohedral like 
calcite; RA R=107° 40'; crystals often an acute rhombohedron ; 
anhydrous. 
HYDROZINCITE, p. 157. H.—2-2°5; G.=8-6-3°8; white, gyh, 
ywh, often earthy ; reacts for zinc ; hydrous. 
D. INFUSIBLE ; B.B. ON COAL REACTION FOR NICKEL. 
ZARATITE (Emerald nickel), p. 168. H.—8. Emerald green, streak 
paler. ize 
E. FUSIBLE ; ASSAY ALKALINE AFTER IGNITION. 
WITHERITE, p. 221. H.=3-3-75 ; G.=4:29-4'35 ; trimetric ; white, 
ywh, gyh; B.B. fuses easily, flame ywh green; anhydrous. ~ 
STRONTIANITE. p. 223 H.=3:5-4; G.=36-3'72 ; trimetric ; pale 
green, gray, ywh, white; B.B. fuses only on thin edges, flame 
bright red ; anhydrous. 
BARYTOCALCITE, p. 222. Monoclinic. G.=3°6-3°66 ; B.B. nearly 
like witherite. 
Other carbonates are the Lead Carbonate, p. 152, and Copper Car-: 
bonates, p. 140, included severally under the heads of LEAD and Cop- 
PER, on page 391. 
