6 



NEW YORK STATE MUSEUM 



There are three classes of the product of the quarries, 1> 

 flagstone, 2) " edge " stone and 3) " rock." The first class in- 

 cludes the stone used for sidewalks and requires little dressing. 

 A stone H inches thick and over, with a smooth surface and 

 edges at right angles, fulfils all requirements. Bluestone is 

 particularly suitable for use as flagging, retaining after long 

 wear its rough surface. " The stone is so compact as to absorb 

 but little moisture, and thus, when used as flagging, ice and rain 

 remain upon it but a short time." " Its hardness resists wear, 

 never forming the slipping surfaces of clay slate." 



The second class includes such stone as curb, window and 

 door sills, lintels and other house trimmings. This stone all 

 requires dressing; curb requires " axing" on the face and edge. 

 This class of stone requires one or more perfect edges for 

 market. 



The third class includes the stone sold in the rough to the 

 dealers for mill treatment. All this is thick stone, varying from 

 4 inches to 5 and 6 feet. It is sawed or planed in the mills for 

 platforms, steps and building stone. 



The products of the first two classes are often treated in the 

 mill when orders call for such finished work. 



The kinds of stone as to shape, size and use are more numer- 

 ous than the uninitiated would imagine. 



As regards the microscopic structure and quality of the stone, 

 the following notes by F. L. Nason 1 are interesting. 



Bluestone. Bigelow bluestone co. (now Ulster bluestone co.) 

 Minerals: quartz and feldspar. The quartz is in grains, which 

 appear to be very angular in shape, more like a breccia. The 

 grains are clearer than those of other sandstones examined, 

 and the proportion of quartz grains to the rest of the matter 

 is smaller. The feldspar observed differs very materially from 

 that in the other stone. Grains of triclinic feldspar are ob- 

 served, which are very fresh. Another feldspar is almost com- 

 pletely decomposed. No carbonate of lime appears to be 

 present, and very little oxid of iron. The long, wavy, crys- 

 tallike dark spots in the stone appear to be decomposed feld- 



1N. Y. state mns. 47th an. rep't 1893. 1894. p.5S3; X. Y. state geol. 13th 

 an. rep't 1893. 1894. p.389. 



