7:(>li 



1882. 25 Tratis. N. V. Ac. Set. 



over 30 centimeters across and weighing 45 pounds, a single crystal 

 weighing 20 pounds, etc.; all the faces are unpolished. Pyroxene 

 is found in huge crystals, one being 120 cm. long and 45 cm, 

 through. Qrthoclase, in crystals 5 to 15 cm. through. Zircon and 

 fine green fluorite also occur. 



Mr. KuNZ also exhibited minerals, from a new locality at Stone- 

 ham, Maine, which very much resemble those described by Profs. 

 Dana and Brush, from Branchville, Conn. Among these may be 

 mentioned triphylite, triphte, damourite, spodumene, and a pink 

 mineral, as yet unidentified. He had also recognized topaz, a 

 mineral new in that association, never before found in that State, 

 and known to occur at but one locality in New England. A crys- 

 tal of this mineral observed was well-formed but much broken, and 

 measured :^d> cm. across the brachydiagonal ; though others, 15 to 

 18 cm. in length, were destroyed in the process of blasting. He 

 also exhibited a specimen of chalcopyrite, in a rare association, with 

 pyrrhotite and pyrite, from Untersalzbach, Tyrol. 



A paper was read by Mr. N. F. Darton, entitled : 



on the genesis of the ores and minerals in the granu- 

 lar limestone of sussex county, n. j. 



Discussion. 



A member pointed out that the content of crystallized tourmahne, 

 epidote, and beryl, in the " dykes of granite " mentioned by the 

 author, identified these as granite veins instead of true eruptive 

 dykes. 



Prof. T. Egleston remarked that all the crystals of so-called 

 " idocrase " from this region, which he had examined, turned out 

 to be tourmaline. 



Mr. G. F. KuNZ reported that fifty crystals of supposed "ido- 

 crase " from this region, now in the cabinet of the Pennsylvania 

 Geological Survey, were really tourmaline. 



Mr. Darton stated that, at Sparta, the granite holding tourma- 

 line, cut across the limestone beds, and might occur in true veins, 

 and that he believed that crystals of idocrase from Franklin had 

 been identified by analysis. 



