191Jli\ Certain Mineral Resources 95 



investigated for potash feldspar for use in the manufacture of 

 pottery. Formerly this feldspar was too far from transporta- 

 tion to be profitably mined, but now since the railroads have 

 penetrated into these districts, these deposits are available; 

 and several are now being worked in North Carolina. These 

 feldspars contain from 12 to 14 per cent, of potash. 



Masses of quartz which are very pure are found in many 

 of the pegmatitic dikes. It has two possible values: one for use 

 in the manufacture of glass and the other in the manufacture 

 of pottery. At the present time no quartz is being produced 

 from these pegmatitic dikes for commercial purposes, but its 

 prospective value is being investigated. 



With these three raw products that are used in the manu- 

 facture of pottery — occurring abundantly in the Southern 

 States — it is only a question of a little time when pottery 

 manufacturing plants will be established somewhere in the 

 South, and we will stop shipping all our raw products north 

 and buying them back again in various forms of clay manu- 

 factured products, thus paying double freight rates. In the 

 vicinity of many of the pegmatitic dikes are water powers which 

 would be available for grinding the quartz or feldspar in prep- 

 aration for use in pottery works. 



RAKE EARTH MINERALS. 



Several of the rare earth minerals have been found asso- 

 ciated with the pegmatites in the Southern States in commer- 

 cial quantity. A commfercial demand having arisen for cer- 

 tain chemical elements or compounds, mineralogical investiga- 

 tions were begun to determine a probable source of these ele- 

 ments, and in many instances the minerals containing them 

 have been discovered in the South. Many of these elements 

 have been required for use in the manufacture of certain light- 

 ing apparatus, as thoria in the manufacture of the mantles 

 for the incandescent lamps ; zirconia and yttria in the manufac- 

 ture of the glower for the ]^ernst lamp ; tantalum for use in 

 the electric bulb; uranium (only experimentally) in the elec- 

 tric bulb ; and tungsten in the manufacture of the tungsten elec- 

 tric bulb. With the exception of tungsten, minerals contain- 



