An Account of some JVew and Extraordinary Minerals. 243 



allel with the crystals of spinelle, often greenish and compact, 

 at other times tinged yellow by an admixture of brucite. 



These crystals bear not the smallest resemblance to the 

 marmolite of Nultall, erroneously referred to serpentine, on 

 the mere ground of chemical affinity, by Mr. Vanuxem. 



In the same mass also are associated very large prismatic 

 crystals of chromate of iron, at least so they appear to be, by 

 the beautiful green colour which they impart to nitrate of pot- 

 ash, having a specif c gravity of 4 30. Some of these prisms 

 are an inch in breadth and two inches in length, with two late- 

 ral faces, broader than the rest. 



The imbedding matrix of the whole is, as usual, crystalline 

 carbonate of lime, with mica and some appearances of hema- 

 titic iron. A few greenish spinelles occurred near the same 

 place, and the neighbourhood abounds with small black and 

 blackish gray spinelles. Not far from the same locality also 

 is found, associated generally with a fine green and crystal- 

 line serpentine, the red spinelle of various shades and degrees 

 of translucence ; when dark it passes into reddish brown, 

 but when smaller and more bri<iht, it approaches to rose red. 

 These are from a line in diameter to three quarters of an inch 

 on each side of the bases ; now and then they occur, in he- 

 mitrope — but are seldom or never emarginated, like the green 

 ceylanite of Franklin. 



At Ryram also, a few miles from Sparta, the red spinelle 

 has been found^by William Ingliss, Esq. Some of these, ap- 

 proaching to a chocolate brown in colour, give a base of one 

 inch and a quarter on each plane. At the same place we 

 have also found the green ceylanite though much inferior ia 

 colour and translucence to that at Franklin, 



The magnitude of other crystals at this place (Warwick) 

 ia equally surprising as that of the spinelles. Crystals of 

 scapolite, terminated, are to be found, each of the six faces 

 of the prisms measuring four inches — or a circumference of 

 twenty-four inches, or even more. They are of course rough 

 and corroded ; but the smaller prisms, often with narrow re- 

 placements on the edges, are very perfect and almost trans- 

 parent — all of these slightly tinged with green. 



Of the amphibole genus we meet with several varieties 

 finely crystallized, the black with six-sided prisms, each face 

 scmetimes is an inch in breadth. Aclynolite in short and con- 

 fused prisms, and a chocolate brown finely crystallized variety, 

 both in large and small crystals, of the usual form, and also 



