PHOSPHATES FROM SOUTH CAROLINA DEPOSITS 41 



Tennessee phosphate were found to have the following com- 

 position : 



12 34 5 



Insoluble (silica, etc.) 1.31 2.56 1.85 2.16 5.87 



Phosphoric acid 36.55 36.55 35.47 35.50 32.85 



Phosphate of lime 79-8o 79.80 77.45 77.50 71.73 



Oxid of iron and alumina 2.00 2.48 3.16 3.88 4.52 



Carbonate of lime 13.27 12.05 11.46 14.29 9.93 



Organic matters and water 3.62 3.11 6.08 3.17 7.95 



The above samples belong to what is known as the Brown Rock 

 and come chiefly from the vicinity of Mt. Pleasant in Maury 

 County. 



43. Blue Phosphate. In Hickman County, which is adjacent to 

 Maury County, large quantities of phosphate rock are found of 

 a bluish gray tint and less rich in phosphate of lime than the de- 

 posits above mentioned. These rocks are found to contain from 

 60 to 70 per cent, of phosphate of lime, and from 2.5 to 5 per 

 cent, of oxids of iron and alumina and from 1.5 to 5 per cent, of 

 silica. The iron exists in these rocks partly in the form of pyrite. 

 In Perry County another variety of phosphate of a reddish or 

 white color is found with a still lower content of phosphate of 

 lime, ranging from 30 to 50 per cent. These samples come from 

 the surface. The interior deposits, on the contrary, are quite 

 rich, containing from 70 to 75 per cent, of phosphate of lime. 

 Still other deposits are found in Tennessee containing from 77 

 to 80 per cent, of phosphate of lime and from two to three per 

 cent, of oxids of iron and alumina. 



44. Phosphates from South Carolina Deposits. It has been 

 estimated that up to the present time there have been fur- 

 nished to the markets from the South Carolina deposits about 

 11,000,000 tons of rock, of which about one-third has gone to 

 Europe. The discovery of the Florida phosphates was a severe 

 blow to the industry in South Carolina, the annual exports from 

 South Carolina having fallen to about 30,000 tons. The reason 

 of this is that the South Carolina rocks are somewhat low in 

 their content of phosphate of lime, ranging between 55 and 60 

 per cent. They contain from seven to n per cent, of carbonate 



