474 MINERALS IN THE [December, 



Where it has been exposed to the atmosphere, it sepa- 

 rates generally into four- sided prisms, with two acute 

 and two obtuse angles, of an inch or two in diameter and 

 five or six long, the ends are broken at right angles with 

 the prism. 



Flint, Quartz agathe pyromaque, H. Fuerstein, W. 



We find this mineral only in rolled pieces in this vi- 

 cinity. It exists in the gravel hills near the Schuylkill, 

 and is also found on the shores of the Delaware, of a 

 black colour, containing the remains of a small zoophyte 

 of a globose appearance. Found near the Delaware above 

 Bristol, enclosing terebratula. 



Chalcedony, Quartz agathe chatoyant. H. Kalzedon, W. 



Many beautiful specimens of chalcedony, were found 

 by Mr. Vanuxem and myself, on the Westchester road, 

 between the sixteenth and seventeenth milestones. It is 

 associated with quartz in decomposed serpentine. Colour, 

 bluish milky white, covered with rich, yellow, drusy, 

 quartz crystals. It sometimes contains arborizations, of 

 a hair brown colour, supposed to be confervae. Mr. Con- 

 rad has also found it betweer.. Springfield and Concord. 



Basanite, Lydlan Stone. W. 



This variety of silecious slate, is found in rolled pie- 

 ces at the falls of the Delaware at Trenton, of a dark blu- 

 ish black colour. It evidently has been brought by the 

 water, from the grawacke and transition limestone forma- 

 tion, in the neighbourhood of Kaston, about fifty miles 

 above. 



