Mineralogy and Petrology, 
October 17, 1938 
Memorandum, to Dr. Schmitt: 
The phosphate rocks of the West Indies have 
been studied only superficially and it is probable that 
they contain new mineral species. The following 
minerals have been described from these deposits: 
* 
Colloph anite: A phosphate of lime found 
at Sombrero, Mona and Moneta Islands* 
Brushite ; An acid phosphate of lime found 
at Aves and Sombrero Islands* 
Metabrushite : An acid phosphate of lime, from 
Sombrero Island* 
M artinite : An acid phosphate of lime found at 
Table~5!Duntain, near St* Barbara, Curacoa. 
Specimens of these minerals are rare in collec- 
tions, although they are probably common at the phosphate 
deposits* No one has ever made a systematic search for 
them* Other mineral species are undoubtedly present and 
these species are likely to be found on other islands* 
Any small crystal-lined cavities or crevices 
should be collected, as these contain minerals in most 
desirable form* 
Very truly yours, 
nt-f- 
Curator, 
Mineralogy and Petrology 
Dr. Waldo Schmitt, 
U. S. National Museum, 
Washington, D. C* 
