Table 2.

– Fluorine concentrations determined by mineral dissolution in acid and measurement using a fluoride selective electrode. Middle column shows amount of fluorine per amount of sample (both organic and mineral phases). Right column shows amount of fluorine per amount of mineral within the sample.

Sample	ppm F within sample	ppm F within mineral phase of sample
0.5 ppm	3890	5120
1 ppm	7610	11,200
2 ppm	11,400	15,200
5 ppm	25,400	30,300
25 ppm	24,300	32,000
50 ppm	27,800	34,700