68 
States of Colombia and Greece. Nearly all the specimens carry 
an appreciable percentage of gold. 
With the stibnite are examples of the rarer oxidized ores of 
antimony, valentinite, etc. 
Ingot antimony and products of smelting stibnite. 
Arsenic ores shown here include the sulpharsenide of iron, 
leucopyrite. Much of the arsenic of commerce comes as a by- 
product from gold or other ores. One such by-product is the 
arsenical flue dust from treating the silver-lead ores of Lauri- 
um, Greece, in which distinct crystals of the oxide or “white 
arsenic” are plainly visible. 
Following the antimony and arsenic ores is a case of ores 
of nickel, cobalt and aluminum. 
NICKEL, COBALT AND ALUMINUM, 
A series of specimens of nickel and cobalt-bearing minerals 
is arranged in the order of their richness: 
They are : 
Linnaeite, cobalt sulphide, 58 per cent, cobalt. 
Siegenite , sulphide of cobalt, nickel and iron, 30 per cent, 
to 40 per cent, nickel. 
Millerite, sulphide of nickel, 64.4 per cent, nickel. 
Smaltite, cobalt and nickel arsenide, cobalt up to 28.S per 
cent. 
Chloanthite, nickel arsenide, up to 28.1 per cent, nickel. 
Cobaltite, cobalt arseno-sulphide, 35.5 per cent, cobalt. 
Niccolite, nickel arsenide, 43.9 per cent, nickel. 
Asbolite, oxide of cobalt, 24 to 40 per cent, cobalt. 
Erythrite, hydrous cobalt arsenate, 29.5 per cent, cotelt. 
Roselite, hydrous arsenate of cobalt, lime and magnesia, co- 
bait, 9.8 per cent. 
Annahergite, nickel’ arsenate. Nickel, 29.3 per cent. 
Bieherite, hydrous cobalt sulphate, cobalt, 20.9 per cent. 
Zaratite, hydrous nickel carbonate. Nickel, 46.7 per cent. 
Genthite, hydrous nickel-magnesium silicate. Nickel, 22.6 
per cent. 
Garnierite, hydrous nickel-magnesium silicate. Nickel, vari- 
able. 
