17-t 



GEOLOGY OF OLD HAMPSHIKE COUNTY, MASS, 



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made up almost entirely of small, shining scales of hematite. I think it is 

 a pseudomorph after the sericite-schist in which it is intercalated. 



Below, the vein changes into a firm, compact magnetite, which is often 

 interlaminated with the qiiartz-rhodonite mixture. 

 The mine has been recently (1891) opened by Mr. 

 Ferd. S. Ruttmanii with improved appliances. 



The flesh-colored quartzite, plainly coloi'ed by 

 manganese, which occurs as a veinstone on Forge 

 Hill and south all along the vein, has the aspect of 

 a common granular quartzite, but under the micro- 

 scope its appearance is very striking. The slide 

 looks exactly as if a layer of half-di-ied blood cor- 

 jHiscles were spread upon it. They average .05™™ 

 across, but vary from half to double this size. They 

 are flattened and circular, but not always entirely 

 regular, have darker centers, and are of reddish color. 

 They are completely apolar, but have at times a 

 polarizing grain at center. Some of them are com- 

 plete trapezohedra, and they are manganesian 

 garnets. A few grains of quartz and a rare scale 

 of chlorite complete the slide. This description is 

 of the rock at Forge Hill. 



From the mine on Cressy's land, on the south, 

 the g-rains are much smaller, .016°"". There is a 

 little more quartz, otherwise they are the same. 

 The rock is thus a coticule or quartz-garnet rock, 

 tinted flesh-color by manganese, and is a product 

 of the same heated waters which have filled the 

 vein with hematite. 



It is at times marvelously contorted, as illus- 

 trated Ijy tig 10, taken from a band at the mine 

 on Forge Hill. This in appearance is a tine-gi'ained, 

 pink sandstone. The folds are so nearly sheared 

 apart that a piece falls asunder easily in coarse bars, and the whole surface 

 is frosted over with specular iron. Few traces of the iron can be found 

 fartlier north, but south of the point where the fault line is made to terminate, 



