REPORT OF THE STATE GEOLOGIST. li 



KAOLIN. 



In addition to the kaolin already mentioned in Robertson County, 

 kaolins of excellent quality are found in Edwards and Uvalde counties. 

 These are pure white in color, somewhat greasy to the touch, and are 

 infusible in the hottest blow pipe flame. Being practically free from 

 iron, they are adapted to the making of the best grades of china. They 

 are free from grit and every other objectionable impurity. A compari- 

 son of the analyses of these kaolins with those of established reputation 

 will more fully show their value. The analyses of the Texas specimens 

 are by Dr. Everhart, of the State University: 



Nassau, Ivrieux, Devonshire, Nueces Co., Edwards Co., 





Germany. 



France. 



England. 



Texas. 



Texas. 



Water 



18. 



13. 



12. 



4.53 



6.05 



Alumina 



32. 



27.30 



38. 



33.66 



43.17 



Silica 



45.06 



46.80 



47. 



46.60 



48.41 



Lime 



74 







.43 



.38 



Magnesia 









.96 



.10 



Alkalies 





2.50 



1.76 



1.65 



1.78 



Oxide Iron . . .... 



90 











Of the other materials needed in the manufacture of pottery we have 

 deposits of feldspar well suited for glazing; gypsum for the manufac- 

 ture of plaster of paris for moulds ; clays suitable for the saggers, and 

 cheap fuel in abundance. 



BUILDING MATEEIALS. 



BUILDING STONE. 



The variety and widespread occurrence of the rocks of Texas suitable 

 for construction is so great that it will be impracticable to allude to them 

 in any other than general terms. They will therefore be grouped under 

 general headings. 



GKANITES. 



Granites occur in widely separated portions of the State. The first 

 locality is what has been termed in our reports the Central Mineral 

 Region, the second is in the extreme west, or Trans-Pecos Texas. The 

 granites of the first or Central region are of different colors. The best 

 known is the red granite, such as was used in the construction of the 

 Capitol building. The color is red to dark reddish-gray, varying from 

 fine to rather coarse grain in structure, and susceptible of high polish. 



