84 NEW YORK STATE MUSEUM 



dark blue, running in places to almost dark blue which is the color 

 most sought for. In the lighter mottled sorts, the grain is coarse 

 and somewhat irregular, with the light and darker calcite segregated 

 more or less into separate areas. The individual calcite grains 

 mostly have a diameter of about 1 or 2 mm. In the dark blue 

 marble, however, the grain is much finer, the calcite averaging only 

 a fraction of a millimeter in diameter. The variation in color seems 

 to be traceable to the presence of graphitic carbon which is scattered 

 irregularly through the mass in submicroscopic particles. The pres- 

 ence of carbon was indicated in the chemical analysis, but no deter- 

 mination of it was made, the actual amount being extremely small. 



The marble is susceptible of high polish and has a luster very 

 much like that of some gray granites. It is well adapted for monu- 

 mental work and the better grades are mainly used for that purpose. 

 Its weathering qualities are attested by nearly a century of use as 

 monumental and building stone. For building purposes it has found 

 considerable sale in the large towns and cities of New York and ad- 

 joining states, especially for public structures, churches and fine 

 residences. 



The rock face which is most favored for buildings has a medium 

 gray tone, while the cut or patent hammered surface of trimmings 

 shows much lighter. The selling prices vary with the color and 

 uniformity, and range up to about $4.70 a cubic foot which is the 

 price received for the best quality of extra dark monumental stock, 

 sand rubbed but not polished. The lighter grades of monumental 

 stone bring from $1 to $2 less a cubic foot. The grades of the 

 different quarries do not correspond closely, so that the terms dark, 

 extra dark, etc., as used by the several companies are not strictly 

 equivalent. 



There seems to be some relation between the color of the marble 

 and the stratigraphic features, though such relation may not be 

 uniform or consistent throughout the belt. In general, however, 

 the lighter and coarser marble is on top or in the northwestern 

 section, while the fine-grained dark comes from the structurally 

 lower beds on the southeast. This is indicated by the variation in 

 the different exposures and by the results of drilling. 



The St Lawrence Marble Quarries. The quarries owned by 

 this company are near the northeastern end, two of which are 

 close to the mill and are known as the St Lawrence quarries. The 

 third quarry, called the extra-dark, is on a different vein to the 

 south and east. Only the last was under operation at the time of 



