32 Geological Reports on the State of New York. 



In Herkimer County, there are beautiful rock crystals at Mid- 

 dleville ; they are numerous, and, except when they contain some 

 foreign substance, as anthracite, are very perfect both in form and 

 transparency. 



In certain shales and sandstones, there are in tWTs county rich 

 beds of iron ore, usually red and oolitic ; there are in different situ- 

 ations, one to two or three beds of the iron ore, and it appears to 

 have been deposited as an ore, when it met with an impervious 

 stratum ; and when the latter was pervious, the iron was absorbed 

 and colored the rock. 



In a sandstone in the town of Starke, gypsum was discovered 

 in mining for silver ; this g^T'psum is here white, both before and 

 after calcination. 



The water limestone series occurs in thin layers, rarely more 

 than 2 or 3 inches thick, of a uniform drab, and effervescing with 

 acids. 



"In the limestone at the Falls of Niagara, and of numerous other pla- 

 ces, and in some of the water limes below that limestone, there is at the 

 separation of the layers a singular columnar appearance, presenting itself 

 at right angles to the layers, extending unequally as to length, bearing no 

 small resemblance to the sutures of the skull. When examined they show 

 the impress of a parallel fibrous or striated appearance, which is almost 

 invariably covered with minute scales of coaly matter. In vain I sought 

 last year for the cause of this common appearance. In examining the 

 upper layers of the water lime in Herkimer, the difficulty was solved : 

 specimens were discovered with the striae, and with carbonate of lime in 

 minute fibres as to thickness, but not in length, clearly proving that the 

 phenomena in question were caused by the crystallization of a saline sub- 

 stance in fibrous crystals at the joints of the rock, analogous to those beau- 

 tiful productions which all are familiar with, namely, the congelation or 

 crystallization of water in loose and spongy soils. This explanation meets 

 its confirmation in a specimen recently examined, which I brought last 

 year from the Falls of Niagara, in which the striated appearance is finely 

 exhibited, the specimen being exceeding fresh and unaltered; on the top 

 of the black or carbonaceous coating there are two small groups of fibrous 

 sulphate of magnesia, which the force of crystallization has ejected since 

 being in the cabinet, to the height of a quarter of an inch, and for want 

 of a support the ends coil over, as we find in the black part of the banks 

 of our ditches and other low grounds. 



"From finding last year the sulphate of magnesia with common salt as 

 an efflorescence, below the upper falls at Rochester, and knowing that 



