BUTLDINfJ AND ORNAMKNTAL STONKR. 445 



theory that the quarry wator hoUls in solution certain ol" the cementinj^ 

 materials, as has been already uoted (p. 339). 



{b) Varieties of Sandstones. 



Many varieties of sandstones are popularly recognized, the distinc- 

 tions being founded upon their composition, structure, the character of 

 the cementing material, or their working qualities. ArJioseia a sand- 

 stone composed of disintegrated granite. FernujinouH, .siliccotis, and 

 calcareous sandstones are those in which these substances form the ce- 

 menting nmterial. Argillaceons sandstones contain clay, which can 

 easily be recognized by its odor when breathed upon. FUtf/sfonr is a 

 sandstone that splits readily into Ihin sheets suitable for tlagging ; the 

 same term is ai)plied to other rocks, as the schists and slates, which 

 serve a similar puri>ose. Frcfslones are so called because they work 

 freely in any direction, their bedding or grain not being stiongly enough 

 marked to in any way interfere with this property, (iraijwarlce is a com- 

 pact sandstone composed of rounded grains or fragments of quartz, 

 feldspar, slate, and other minerals, cemented by an argillaceous, calca- 

 reous, or feldspatliic paste. This term is no longer in g<Mieral use. 

 Qii(irf.:lies result from the induration of san<lsl()nes, a lesult brought 

 about either by pressure or, more commonly, by the deposition of sili(;a 

 between the granules. 



Sandstones occur among rocks of all ages, from (he Archaean down to 

 the most recent ; none are, however, at present used to any great extent 

 for building purposes in this country that are of later origin than Trias- 

 si<!, or possibly Cretaceous. In the list of natural building materials 

 of the United States sandstone ranks third in iin])ortauce ; the census 

 returns for 1880 showing a product of 21,770,930 cubic feet, valued at 

 $4,780,391. 



(c) Sandstones op the Various States ani> Territories. 



Alabama. — On the line of the Alabama Great Southern Hallway, sonn^ 

 GO or 100 miles from Chattanooga, T(Min., tlierci occurs a yellow sand- 

 stone that is sufliciently soft when iirst quari ied to be cut with an a\, 

 and which hardens sufliciently on exposure to be very durable in that 

 climate. Samples of this stone received from De Jvalb County are o( 

 decidedly inferior (juality. 



Ari::ona. — There is at present little demand for building stone in this 

 Territory, and conse(iuently but little is known regarding its available 

 material. From Yavapai County, on the line of the Atlantic and Pa- 

 cific; Railroad, we have received a block (No. 35571) of tine grained, com- 

 pact, light-pink sandstone, that from its warm and j)leasing color and 

 easy working <]ualities would be eagerly sought by Eastern buihlers 

 were it more accessible. So far as we ai-e informed, it is not at i)resent 

 cpiarried to any extent. 



Arl'ansas. — IJrown massive^ "freestone" that will make a good l)uild 

 ing stone is stated by Owen* to occur in \'an lUiren County. 

 ''Gcol. of Arkansas, 1858, p. 75. 



