•282 DESCRIPTIVE MINERALOGY. 



3.11 to 3.25. Before the blowpipe, it is infusible, or fuses with great difficulty, but it loses 

 its colour and becomes opaque. With borax, it fuses slowly but completely, into a transpa- 

 rent glass tinged by iron. The brown varieties act slightly on the magnetic needle. It is not 

 acted on by acids. Acquires negative electricity by friction. 



Composition. Magnesia 54.00, silica 32.67, fluoric acid 4.09, oxide of iron 2.33, potash 

 2. 10, water 1 .00 {Sei/bcrt). It is supposed to be a fluo-silicate of magnesia. 



Geological Situation. It occurs in white limestone, associated with graphite, spinelle, 

 hornblende and other minerals. It has seldom been found in any other rock. 



LOCALITIES. 



Orange County. Chondrodite of almost every variety of colour, and sometimes imper- 

 fectly crystallized, is found in various parts of this county. It is usually associated with 

 spinelle, and is imbedded in white limestone. In the town of Cornwall, three miles west of 

 West-Point, and in the Forest of Dean, it is in small grains, which are usually of some shade 

 of yellow. In the town of Monroe, at the so called Silver mine, it has nearly the same cha- 

 racters. Near Greenwood furnace, and at Two ponds, it is also found in light coloured grains 

 in the usual gangue, and with the usual associate, spinelle. The same remarks will apply 

 to its occurrence at Fall hill, in the same town. 



In the town of Warwick, the localities are very numerous. Indeed it is more or less 

 abundantly disseminated through all the beds of white limestone. Fine specimens may be 

 obtained on the land of Mr. Houston, near Edenville. The principal colours are blood-red, 

 orange and buff. The masses often have the appearance of highly modified crystals, but they 

 are too imperfect to admit of measurement. The specimens from the vicinity of Amity are 

 usually of a light yellow colour, are associated with spinelle, and, as in all the other cases, 

 are in the white limestone. 



After what has been said of the abundance of chondrodite in this county, it is unnecessary 

 to extend the notice of particular localities. It is worthy of remark, that although there is so 

 great a similarity between the minerals and rocks of Orange county and those of Northern 

 New- York, chondrodite, so abundant in the former, is rarely found in the latter. 



The occurrence of chondrodite in the limestone of Orange, has been referred by some to 

 the segregation of the magnesia which it contains, and all the accompanying minerals have 

 been considered as the direct result of the metamorphosis which the rock has undergone. 

 Without wishing at present to reject this view, I would simply suggest whether, if it is cor- 

 rect, we might not fairly infer that chondrodite and spinelle should be found abundantly in the 

 dolomite or magnesian limestone of New-York, Westchester, Putnam and Dutchess counties. 

 But so far from this, chondrodite has not hitherto been found in even the smallest gi'ains in 

 this rock. There is, it is true, a doubtful locality near Carmel ; but here, if in fact it does 

 occur, it is associated with magnetic iron ore, hornblende and mica. I now believe the 

 mineral to be a variety of serpentine. 



