DETERMINATION OF MINERALS, 389 



IL MINERALS, NOT ELEMENTS, THAT 

 ARE WHOLLY VOLATILE B.B. 

 ON COAL. 



1. Lustre metallic ; streak metallic. 



TETRADYMITE, p. 102. G. =7 2-7 '9 ; pale steel-gray; so soft as 

 to soil paper ; on coal white fumes ; flame bluish-green; sometimes 

 sulph. odor ; in open tube, a coating which fuses to white drops. 



BISMUTHINITE, p. 102. G. = 6'4-72; whitish lead-gray; on coal 

 yellow coating and sulph. odor. 



STIBNITE, p. 100. G. =4-5-452; lead-gray; on coal dense wh. 

 fumes and wh. coating . 



2. Lustre unmetallic ; streak same nearly as color. 



ORPIMENT, p. 99. Lemon yellow ; on coal burns, odor alliaceous. 

 REALGAR, p. 99. Bright red ; on coal burns, odor alliaceous 

 ARSENOLITE, p. 99. White ; on coal, odor alliaceous. 

 VALENTINITE, p. 101. White ; on coal dense wh. fumes, inote. 

 CINNABAR, p. 128. Red ; in open tube, sulph. odor, coating of 



mercury globules. 

 SALMIAK, p. 230. White ; saline and pungent taste ; on coal, fumes 



of ammonia. 



III. COMPOUNDS OF GOLD, SILVEE, MEK- 

 CURY, COPPER, LEAD, TIN, CHRO- 

 MIUM, COBALT, MANGANESE. 



A. Yielding a malleable globule B.B. on coal, with 

 or without soda 



1. COMPOUNDS OF GOLD, 



Yield gold, or an alloy of gold and silver, B.B. on coal. The tellu- 

 rium ores, pp. 115, 116, give a coating of drops of tellurous acid in 

 open tube. 



2. COMPOUNDS OF SILVER. 



B.B. easily fusible ; Gt. above 5 ; yield, with few exceptions, a glo- 

 bule of silver (white and malleable), on coal, with soda, if not without ; 

 and, in the exceptions, silver globule obtained by cupellation. All 

 have metallic lustre excepting cerargyrite, bromyrite, and iodyrite, 



