Among these were the Siberian and Brazilian topaz, borate of magnesia, mesotype, sphene, and calamine.
"Catholic Churchmen in Science"
James J. Walsh
The sources of these materials are perhaps deposits of the type mentioned in the last paragraph, or, in California, certain Tertiary borate deposits described below.
"The Economic Aspect of Geology"
C. K. Leith
This is the only important case known of borate deposits of marine origin.
"The Economic Aspect of Geology"
C. K. Leith