N 4 -’1909 
JOURNAL 
OF THE 
library 
NEW YORK 
botanical 
garden. 
Elisha Mitchell Scientific Society 
NOVEMBER, J9C8 
VOL. XXIV. NO. 3 
MONAZITE AND MONAZITE MINING IN THE CAROLINAS* 
BY JOSEPH HYDE PRATT AND DOUGLAS B. STEKRETT 
Introduction 
Monazite is one of the minerals which for a long time was con- 
sidered rather rare in its occurence, but upon a commercial de- 
mand arising for it prospectors and engineers soon located large 
deposits of it in the Carolinas and Brazil, and the supply has al- 
ways been able to meet the demand. During the past year 
further sources of supply of monazite have been discovered and 
developed in Idaho. North and South Carolina, however, are the 
only states that have thus far put any monazite on the market. 
This mineral is essentially an anhydrous phosphate of the rare 
earth metals, cerium, lanthanum, and didymium (Ce, La, Di) P0 4 . 
There is nearly always present a varying but small percentage of 
thoria (ThOj and silicic acid (Si0 2 ), which are very probably 
united in the form of a thorium silicate (ThSi0 4 ) . Some mona- 
zites contain but a fraction of a per cent of thoria, while others 
have been recorded that showed the presence of 18 to 32 per cent; 
♦Paper read at the Chattanooga meeting of the American Institute of Min- 
ing Engineers, October 1908. 
v.m] 
Cl 
Printed November 13, 1908 
