30 GEOLOGICAL REPORT. [1F53, 54, 55 



USEFUL MATERIALS OF THE ORANGE SAND FORMATION. 



53. These consist of Sands, Gravel, Building Stones and Clays of 

 various kinds. 



Sands. — In regard to these little need be added to what has 

 been said in the general description of the formation. (See 11 10 

 ff.) They almost always contain more or less clay, which usually 

 is what imparts to them their various colors ; even when the color 

 is white. In most cases (except those of ochreous tints, when the 

 single grains are often covered with a hard crust of iron rust), 

 washing will readily separate the mass into white quartzose sand 

 and clay of a corresponding color ; and hence the sand washed 

 out of this formation by the streams, is generally white, and thus 

 far well adapted to the purposes of the mason and plasterer ; 

 although, whenever the sand of other formations is accessible, it 

 is commonly preferred to that of the Orange Sand formation, on 

 account of the rounded shape and smoothness of the grains, which 

 characterizes the latter, and is less favorable to the cohesion of the 

 mortar in which it is used. 



The sand deposits of the Orange Sand formation cannot usually 

 be relied on much for continuity, their stratification, as has been 

 stated, being extremely whimsical. 



54. Gravel or Shtngle. — Its regions of occurrence have been 

 sufficiently defined for practical purposes, in a previous paragraph 

 (1 178 ff.) In a State where stones are scarce, a liberal sup- 

 ply of gravel for the improvement of streets and roads is likely to 

 be appreciated. The deposits of the eastern border of the State 

 do not as a general thing furnish gravel of equal purity with the 

 beds bordering on the Mississippi, and are more frequently cemen- 

 ted so as to form loose puddingstones ; which are rarely of suffi- 

 cient coherence to serve for building purposes, while yet too hard 

 to be broken up for gravel. 



55. Gems of some value and of great beauty may sometimes be 

 picked up among the pebbles of agate, cornelian, chalcedony, sard 

 and jasper, which are most abundant in the S. W. portion of the 

 State ; commonly, however, the larger agates are cellular, with 

 sharp incurrent and excurrent angles, so as to greatly reduce 

 their available mass. They may often be recognized, among the 

 mass of pebbles, by this irregularity of external form. The 



