354 Clicmical ComposiHon and Commercial Value of 
it is found in several places in the Tyrol and Switzerland, also 
in Boliemia, Saxony, Bavaria, Sweden, and Norway. Most 
commonly it occurs in thin seams, imbedded in crystalline or 
volcanic rocks, but seldom in sufficient quantity to repay the 
cost of working. 
Mineralogists distinguish several varieties of apatite. Some 
specimens are regular crystals, others crystalline, others foliated 
or conchoidal. The colour varies as much as its crystalline 
structure ; l)ut, generally speaking, apatite has a light green or a 
reddisli colour. The apatite which at present is imported into 
England from Norway is found chiefly at Krageroe. 
Two specimens of red-coloured apatite furnished, on analysis, 
the following results : — 
No. 1, No. 2. 
Hygroscopic water '43 '43 
Water of combination -40 '40 
'Phosphoric acid 41-88 41*74 
Lime 53-45 54-12 
fChloride of calcium 1-Cl 1-61 
Magnesia .. -20 
Phosphate of iron and alumina -66 -45 
Insoluble siliceous matter 1-24 -97 
Alkalies -30 
99-67 100-22 
* Equal to tribasic phosphate of lime (bone-earth) 90-74 90-44 
t Containing chlorine 1*03 1-03 
These specimens had a bright red colour like ironstone, and 
yet they contained but very little oxide of iron. Two other 
samples of very light green-coloured, almost white, apatite from 
Krageroe, were found to contain : — 
No. 1. No. 2. 
Hygroscopic water -19 '298 
Water of combination -23 '198 
^Phosphoric acid 41-25 42-28 
Lime 50-62 53-35 
f Chloride of calcium 6-41 2-16 
Oxide of iron -29 1 
Alumina -38 > 
Potash -04 . 
Soda .. ..1 -13 
Insoluble siliceous matter -82 -99 
100-36 100-196 
* Equal to tribasic phosphate of lime (bone-earth) 89-37 91-60 
t Containing chlorine 4-09 1-38 
It will be seen that these samples of Norwegian apatite con- 
tain a very high percentage of phosphate of lime, only a small 
amount of foreign impurities, and no carbonate of lime whatever. 
They are also perfectly free from fluorine, which is present in 
