Abstract
The fluoride in calcareous sinters was colorimetrically determined by Sen Gupta's method, modified by Akaiwa. The fluoride content varied from 450 to 4400 ppm for aragonitic sinters, and from 150 to 1150 ppm for calcitic sinters. The amount of fluoride incorporated into the sinters depends on the crystalline form of calcium carbonate, and on the chemical characteristics of the sinter-depositing waters. A high pH of the waters results in decrease in amount of fluoride uptaken by the sinters.
