EOLIAN MARBLE. 

 We divide all the varieties chemically, into six general divisions : 



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1. Pure carbonate of lime, embracing the marbles and most of the limestones. 



2. Impure carbonate of lime ; the lime portion in excess. 



3. Magneaian limestones and dolomites. 



4. Clay slate, often calcareous. 



5. Talcose schist and talcose limestones. 



6. Quartz rock, and those calcareous rocks in which silicious matters are the principal ingredients. 



I. & II. CAEBONATES OF LIME. 



Under this head we notice particularly the white, colored, variegated and brecciated 

 marbles, saccharoid limestone, variously colored limestone, sparry limestone, brecciated 

 limestone, micaceous limestone, etc. The most important analyses of them are given in 

 the adjoining table. 



Locality. 



White marble, Hyde's Quarry, Rutland, 

 Greenish marble, do., do. 



Statuary marble, Brandon, 

 Marble, Manly's Quarry, Sudbury, 

 Marble, Phelp's Quarry, Middlebury, 

 Marble, Sheldon & Slason, W. Rutland, 

 Limestone, North Dorset, 

 Limestone, Milton, 

 Marble, Sudbury, 



The greater part of the group the non-magnesian usually the pure limestones, as in 

 Massachusetts, occupy the west border, and the dolomites the eastern ; and the interme- 

 diate varieties occupy the interspace. The more silicious limestones are also near the 

 eastern or upper limit, as the limestone is gradually passing into quartz rock. The white 

 statuary marbles have very little impurity in them, as the analyses show. The colored 

 marbles have various impurities in them, from whence their colors are derived. The 

 variegated marbles, like those at Whiting Station on the R. and B. R. R., have a consider- 

 able foreign matter in them, and on this account are often more beautiful. A marble at 

 Arlington is made of fragments of a previous bed, which have been cemented together by 

 stalactitic matter ; i. e., by carbonate of lime held in solution by the water trickling 

 among the fragments. This is a very interesting example ; showing, as it does, that 

 a marble may be broken into fragments and be reconsolidated by the help of small 

 amounts of water permeating the mass. The varieties of marbles are very great, and 

 we refer to the Economical Report for a full description of them. 



The limestone in the vicinity of the marbles is more or less saccharoid. Or it may be 

 slaty, granular and more or less friable. In general the Eolian limestone of Vermont is 

 whitish and rather firm ; not very granular, and though metamorphic not generally abun- 

 dantly crystalline. In this respect it is less marked than in Massachusetts, perhaps for the 

 reason that it is not so highly metamorphic. A few specimens are like the most beauti- 

 fully crystalline marble from one of the quarries at North Adams, made up of completely 



