».o. 76 ] 



125 



GYPSUM. 



(Mineralogy of New- York, page 237. 



Beautiful and very perfect crystals of selenite, have been obtained 

 from the deep boring at Lockpit, in Wayne county. They are found 

 imbedded in gypseous marl, which contains chlorides of sodium and 

 magnesium ; the whole probably formed by the evaporation of the brine. 

 The crystals are six-sided prisms, from half a line to two lines in diam- 

 eter, and from one-fourth to five eighths of an inch in length. They are 

 extended in the direction of//; P on / 124° 41' 43" ; / on/, 110° 

 36' 34". They frequently exhibit the primary plane M. 



A careful trial yielded 21*20 per cent of water. 



Several localities of this mineral occur, according to Prof. Mather, 

 in the 1st Geological District, but none of them are of special import- 

 ance. See Mather^s Rep.^ p. 84. 



APATITE. 



(Mineralogy of New- York, page 239.) 



To the localities of this interesting mineral, I have to add its occur- 

 rence in Putnam Valley, Putnam county ; for which discovery we are 

 indebted to Mr. Cyrus Fountain, of Peekskiil. 



In the Mineralogy of New-York, I noticed the occurrence of apatite 

 as an associate of magnetic iron ore, at several mines in Essex county. 

 Prof. Emmons states that it is also found similarly at the Rutgers mine, 

 in Clinton county. It is sometimes in large crystals upon the walls of 

 the vein, but it is so extremely brittle that it will be very difficult to 

 procure it in a good form for the cabinet. Amer. Quart. Jour., i. p. 60. 



Some diCference of opinion still prevails, in regard to the modes in 

 which apatite has been formed. Mr. J. D. Dana maintains {Sill. Jour. 

 xlvii. 135,) that the apatite found in white limestones, although now in 

 superbly finished crystals, originated from organic structures, from co- 

 rals, which, after being enclosed in their rocky prison, were exposed to 

 intense heat, and hence were decomposed, &c. Dr. Emmons objects 

 to this view, as a general theory of the formation, and in support of his 



