74 
GOLD. 
Case 1. — Type specimens showing modes of occurrence of 
gold in nature. These 2^x^—crystallized gold, Breckenridge, Colo- 
rado; placer gold, Washington; free gold in quartz, California; 
associated with iron and copper pyrites, Colorado, (note the differ- 
ence in color between these and the metal, since they are often 
confused. Gold is soft, ductile and malleable, the pyrites are hard 
enough to strike fire with steel and are brittle); combined with 
telluriu 77 i in sylvanite, petzite, etc., Colorado, (these are called the 
telluride ores); in slate, California. 
Remainder of Case 1. — Gold ores. California. 
Cases 2, 3 and 4. — Gold ores. Colorado. The collection 
from the Cripple Creek mines is especially notable, these ores 
being remarkable for their richness. 
Case 5. — Gold ores. Australia. 
Case 6 . — Gold ores. Mexico. 
Case R. — Collection of nearly all the known alloys of gold 
and silver with copper, tin, zinc, lead, arsenic, and other metals. 
Collection illustrating methods of saving gold and silver practiced 
by Messrs. Tiffany & Co., New York. Here are shown wash 
water, concentrates from an exhaust blower that collects the dust 
of the shops, pieces of flooring of the shops and shoes worn by 
workmen, and beside each of these are placed buttons of gold 
and silver obtained from articles of similar size to those shown. 
Case C. — Large specimens of gold ores. Colorado and New 
South Wales. 
Cases T and U.— Center of the hall. Collection of gold 
nuggets from the placer deposits of Kittitas County, Washington. 
These are flattened and rounded grains found in the river gravels 
from which they are separated by washing. The largest nugget 
in the cases weighs 13^ ounces, which at the standard price of 
gold, $20.67 ounce, would have a value of $279.04. The entire 
weight of the gold shown is 133 ounces, 10 pennyweights. 
A series of photographs illustrates methods of placer mining. 
These vary/ in effectiveness from the crude miners* pan used in 
California in 1849, to the modern hydraulic methods, which consist 
of disintegration of the auriferous alluvium by the propulsion of 
