G6 DESCRIPTIONS OF MINERALS. 
Sulphuric and Sulphurous Acids, 
Sulphurie acid is occasionally met with around volcanoes, 
and it is also formed from the decomposition of hydrogen 
sulphide about sulphur springs. 
It is intensely acid. Composition, Sulphur teroxide (SO,) 
81:6, water 18°4=100, it being chemically hydrogen sul- 
phate. Occurs in the waters of Rio Vinagre, South America ; 
also in Java, and at Lake de Taal on Luzon, in the East 
Indies ; in Genesee Co., N. Y.; and at Tuscarora, St. Davids, 
and elsewhere, Canada West. 
Sulphurous acid, or sulphur dioxide (SO,), is produced 
when sulphur burns, and causes the odor perceived during 
the combustion. It is common about active volcanoes. It 
destroys life and extinguishes combustion. Composition, 
Sulphur 50°00, oxygen 50:00. | 
Native Tellurium. 
Hexagonal; RAR = 86° 57. Occurs sometimes in 
six-sided ‘prisms with perfect /ateral cleavage ; but is com- 
monly granular massive. Color and streak tin-white. Brit- 
tle, dH. = 22% G, =6 156-3. 
Sometimes contains a little iron, and also a trace of gold. 
In an open tube, B.B. yields a white inodorous sublimate, 
which may be fused to colorless transparent drops; and on 
charcoal fuses and volatilizes, tmging the flame green, and 
covering the charcoal with white tellurium dioxide. 
Obs. Occurs in Hungary and Transylvania ; also, Boulder 
Co., Colorado, at the Red Cloud Mine ; in Magnolia District 
at the Keystone, Dun River, and other mines; in the Bal- 
lerat District at Smuggler Mine; in Central District at the 
John Jay Mine, where masses of 25 pounds weight are re- 
ported to have been found. 
Tellurium is also a constituent of ores of silver and lead (pp. 118, 149), 
and these are the chief sources of the metal. 
Tellurite or Telluwrous acid, TeO,, occurs at the Keystone, Smug- 
gler, and John Jay Mines ; especially the last, where it is in minute 
white or yellowish crystals having one eminent cleavage. 
Molybdenite.—Molybdenum Sulphide. 
Hexagonal. In hexagonal plates, or masses, thin foliated, 
like graphite, and resembling that mineral. H.= 1-1°6. 
G. = 4:45-4°8. Color pure lead-gray; streak the same, 
