66 
ZINC. 
The six cases along the wall from the last of the copper 
ores to the entrance to Hall 63 contain the zinc ores, which will 
be encountered in a geographical order, the reverse of that of 
the copper ores. That is, the foreign ores come first and the 
American after. Three immediately adjacent floor cases contain 
the larger and more choice specimens. With the zinc ores 
are placed the ores of the allied but little used metal cadmium. 
The wall case nearest the copper ores contains .foreign zinc 
ores, of which the most important represented in the collection 
are the English and Welsh, the Greek and the Spanish. The 
original black jack of the Welsh miners is here represented and 
may be profitably compared with the ordinary yellow and brown 
blendes, which are often miscalled black jack in this country. 
Immediately in front of this case are two floor cases, one of 
German zinc-lead ores, which should be studied in connection 
with the German ores of other metals, shown elsewhere. The 
other floor case contains choice examples of the zinc ores of 
Laurium, Greece, which have long been famous for their varie- 
ties of color and richness of luster, making them very attractive 
to the eye. They are chiefly the carbonate, smithsonite. 
Additional Spanish zinc ores occupy the bay of another wall 
case, the upper part of which contains the zinc ores of Arkansas. 
The great purity and richness of the American zinc ores, as 
compared with the foreign, is at once apparent, even on casual 
inspection, and this high quality will be noted in all the succeed- 
ing cases which contain American ores. In this case there is a 
collection of the final, intermediate, and bye-products of the 
smelting of zinc ores as carried out at LaSalle, Illinois. Fol- 
lowing the Arkansas ores are two cases of zinc ores from Mis- 
souri, the principal zinc producing state. Included with these are 
the Kansas ores, which form a continuation of the same de- 
posits. . 
With the Missouri ores are shown ores from the similar 
deposits of Wisconsin and Western Illinois. These ores av 
darker than those of Missouri, owing to the enclosu- 
tuminous matter. Another visible difference is in the xrequw.. 
flat or tabular form of the Wisconsin ores and the presence of 
larger quantities of sulphides of iron. Large specimens of Mis- 
souri ores are in an adjacent floor case. 
