83 
HALL*! 78. 
inON^METALLIC MINERALS USED IN CHEMICAL 
MANUFACTURE AND FOR OTHER INDUSTRIAL 
PURPOSES. 
Case 1. — “The Stassfurt Salts.” These salts are rich in 
potash and magnesia, and furnish nearly the whole of the world's 
supply of potash. 
Case 2. — Cryolite and its uses. Salt. The process of mak- 
ing soda and alumina from the mineral cryolite is fully illustrated. 
Case 3. — Borates. The minerals from which borax is ob- 
tained and their products. 
Case 4. — Gypsum. This is a hydrated sulphate of lime, 
from which plaster-of-paris and the fertilizer land-plaster are 
made. 
Case 5. — Sulphur. Native sulphur from many localities. 
Examples of metallic sulphides from which sulphur compounds 
are obtained. Forms in which sulphur comes to market. 
Cases 6 and 7. — Asbestos. Crude and manufactured. 
Asbestos from all the localities where it is obtained for commer- 
cial purposes, together with many other specimens from nearly 
all American localities. Examples of all kinds of manufactured 
asbestos, as packing, ropes, gloves, etc. 
Case 8 .— Mica. Thin plates from American and Russian 
quarries of commercial importance. Mica prepared for the mar- 
ket. 
Case 9. — Mineral wool, crude, and made into non-conduct- 
ing coverings for pipe, etc. Magnesite from Greece and California, 
crude and calcined for use. 
Case 11. — Phosphates. 
Mineral and rock phosphates from well-known localities in 
England, Spain, Canada, Carolina and Florida. Guano from 
Venezuela and Cuba. 
Platform A. — Apatite, Canada. Phosphates, Spain and 
South Carolina. Fluorite, Mineral City, 111. 
Platform B. — Gypsum. Natural Soda. Natural Sulphate 
of Magnesia (Epsom Salts). Alunite, a basic sulphate of potash 
and alumina, and alum made from it. 
