Mineralogy of Orange County, JV. F. 329 



repeated researches in the soil, until at length a space sixteen feet 

 long, eight wide and seven deep, has been completely dug over and 

 examined. This space vs^as occupied by earth, through which were 

 interspersed loose blocks of an aggregate of Limestone Brucite and 

 Serpentine, Spinel in single crystals and in groups, crystals of Brown 

 Hornblende and of Specular Iron Ore. These substances appear 

 to have constituted, originally, a series of crystalline cavities in the 

 Limestone, into which water and soil having freely infihrated from 

 above, they at length became changed to the condition of loose ma- 

 terials. 



The Spinel is possessed of the following colors : black, greyish 

 black, bluish black and reddish brown. The former color has been 

 the most abundant : the latter has never been noticed until lately, and 

 occurs only in one particular spot in this digging ; its gangue is white 

 Limestone. The first mentioned colors belong to crystals either 

 found loose or associated with the Serpentine and Brucite, and are 

 often penetrated by crystals of Specular Iron Ore ; whereas the red- 

 dish brown crystals are penetrated by a crystallized mica of the same 

 color, the plates of which are disposed parallel with the octahedral 

 faces of the Spinel. Nearly all the Spinels of this place are pos- 

 sessed of extraordinary dimensions, varying from one to sixteen 

 inches round the base. A very common size has been from six to 

 eight inches. Nor, as is generally true, is the size at the expense 

 of the perfection of the crystal, the largest being equally perfect, as 

 respects the smoothness and lustre of the faces, with the smallest. 

 We frequently observe a tendency of smaller crystals to unite to 

 form a large one, or of a great number of crystals connected in such 

 a manner that their similar faces are parallel. The only form be- 

 ^de the primitive, in this mineral, is the ordinary hemitrope ; of which 

 several of enormous size are said to have been found. But they 

 have not often been met with of late at this looality. 



The crystals of Specular Iron, above allu- 

 ded to, and which are almost invariably found 

 penetrating the Spinel, are extremely inter- 

 esting on account of their size and form. 

 For a long lime their true character appears 

 to have been misunderstood ; and they are 

 still often found in cabinets under the name of 

 Titaniferous Iron, or believed to be some undescribed ore of Co- 



VoL. XXI.— No. 2. 42 , 



