42 
OUE MINERAL RESERVES. 
owing to the distance the mineral must be hauled to a railroad, while 
smaller mines close to railroad stations are being worked. 
For certain purposes magnesite is used raw, and for other purposes 
it is calcined, and the imports include both kinds. As in the manu 
facture of cement, for example, freshly calcined magnesite seems to 
be superior to old calcined material, there would seem to be a field 
for more extensive calcining and grinding in our own country, 
entirely irrespective of the source of the material. 
FLUORSPAR. 
The fluorspar industry of the United States has shown a steady 
growth from a production of 4,000 short tons in 1884 to 115,580 tons, 
valued at $736,286, in 1913. This notable gain has been conditioned 
largely by the growth of the open-hearth process of steel manufac 
ture, which absorbs about 80 per cent of the fluorspar produced. 
Fluorspar is used also as a flux in blast furnaces, iron foundries, and 
silver, copper, and lead smelters; in the manufacture of fluorides of 
iron and manganese for steel fluxing; in the manufacture of glass, 
enameled, and sanitary ware and of hydrofluoric acid; in the pro 
duction of aluminum ; in the electrolytic refining of antimony and 
lead ; and for many other purposes. 
The increase in the home production and the imposition of a tariff 
on fluorspar in 1909 have resulted in a marked decrease in the 
amount brought in from foreign countries, and in 1913 only 22,682 
short tons was imported, compared with the 115,580 tons produced 
at home. The imports come almost entirely from Great Britain and 
amount to over 55 per cent of the total English production of this 
mineral. The English product entering at New York is able to com 
pete with domestic " spar ” as far west as Pittsburgh. 
There can be no question of the adequacy of the American supply 
to meet all demands in case the English supply is cut off. In 1913 
the output came from Illinois, Kentucky, New Mexico, Colorado, 
New Hampshire, and Arizona, named in the order of yield. Fur 
thermore, the foreign spar is of lower grade than the mechanically 
treated spar from Illinois and Kentucky, and as fluorspar is of value 
chiefly according to its purity, purchasers find that the purer Ameri 
can spar is more efficient and consequently cheaper in the end. 
STRONTIUM. 
The Geological Survey has received in the last few weeks inquiries 
regarding American occurrences of strontium minerals. Many of 
the domestic occurrences are of minor extent and most of them are 
of little commercial value under ordinary conditions. The two 
strontium minerals of commercial importance are celestite (SrSO,)