150 CEMENTS, LIMES, AND PLASTERS. 



the manufacture of carbonic acid. The product will carry about 92 

 to 94 per cent magnesium carbonate, the principal impurity being 

 4 to 5 per cent of silica. 



The principal Grecian deposits are on the island of Euboea, on the 

 east coast of Greece, and also near Corinth. The product is a very 

 pure magnesite, averaging 95 per cent magnesium carbonate. It is 

 low in clayey matter, the principal impurity being 3 to 5 per cent of 



lime carbonate. The Grecian deposits are worked in primitive fashion 

 by pick and shovel. The mines, or quarries, are usually worked as 

 open cuts. As the rock is broken in the mines it is brought to the sur- 

 face, where the magnesite is sorted out. It is then loaded into small 

 carts and drawn to a narrow-gauge gravity railway, when the mag- 

 nesite is loaded into one-ton cars and sent forward to the shipping port, 

 usually Kymassi or St. Theodore. The cost of producing the mineral 

 is about $3.50 per ton, transportation charges to the seaport about 

 $1.00, and freight to the United States about $2.50 per ton. 



Magnesite is found in considerable quantity in southern India, 

 about two hundred miles from Madras. Deposits recently exploited 

 extend over 1500 acres. The railroad from Madras to Calicut runs 

 through these deposits, near the center of the magnesite area. The 

 material can be shipped, in any desired quantity, either from Madras 

 on the east coast or from Beypore on the west coast. As described 

 to the present writer by the owner, the magnesite occurs in beds or 

 veins of varying thickness, from a few inches up to several feet, the 

 magnesite beds being separated by bodies of disintegrated material. 

 An analysis of this magnesite is given in column 1, Table 63. This 

 was made on a 100-ton sample of crude rock. Another analysis of 

 Indian magnesite, quoted in column 2 of the same table, accompanied 

 a series of specimens exhibited at the St. Louis Exposition in 1904. 



American localities. The principal American magnesite deposits 

 are in California and in Quebec, Canada. 



The California deposits are described* as follows: "The principal 

 producing point in California is in the vicinity of Porterville, Tulare 

 County, though a small quantity still comes from Chiles Valley and 

 Pope Valley, Napa County. At Porterville there are several deposits. 

 The main deposit at the opening carries a smaU vein, but at the end 

 of the 240-foot tunnel the deposit is 40 feet wide, and there are said 

 to be several million tons now in sight. At this place calcining furnaces 

 have been erected and are in operation. The mineral crops out boldly in 



* Mineral Resources of the U. S. for 1903, pp. 1131-1135. 1904. 



