J. F. Kemp — Leucite in Sussex Co., N. J. 339 







a 



b 



c 







Hydro-herderite, 

 Hydro-fluo herderite, 



Ca[BeOH P0 4 0-6307 

 Ca[Be(OH . F)J P0 4 0-6206 



• 1 

 1 



0-4274 

 0-4234 



89° 54' 

 very near 90° 







\a 



b 



c 





Wagnerite, 

 Triplite, 

 Triploidite, 

 Sarkinite, 





Mg[MgF] P0 4 0-6362 

 R[RF] P0 4 ? 

 R[ROH] P0 4 0-6190 

 Mn[MnOH] As0 4 06672 



R = Mn and Fe 



1 



1 



1 

 1 



1-5059 



? 

 1-4925 

 1-5154 



71° 53' 



? 

 71 46 

 62 13£ 



In this group fluorine and hydroxyl are isomorphous, and 

 triploidite described by Brush and Dana,* being isomorphous 

 with wagnerite and having undoubtedly the same structural 

 formula as triplite, gave the first instance in which this fact 

 was observed. 



In conclusion the author takes pleasure in expressing his 

 sincere thanks to Messrs. C. S. Bement of Philadelphia, Pa., 

 G-. L. Noyes of Norway and T. F. Lamb of Portland, Me., 

 for the loan of specimens from their private collections and to 

 Mr. L. K. Stone of Paris, Me., for the supply of material from 

 the new locality. 



Laboratory of Mineralogy and Petrography, 

 Sheffield Scientific School, January, 1894. 



Art. XXX Y. — Additional Note on Leucite in Sussex Co., 

 JSf. J. ; by J. F. Kemp. 



In the Journal for April, 1893, pp. 298-305 the writer de- 

 scribed a " Basic Dike near Hamburg, N. J., which has been 

 thought to contain Leucite." The paper dealt with a dike 

 that cut blue, apparently Lower Silurian limestone, was 15-20 

 feet wide and situated about one and one -half miles northwest 

 of Hamburg, N". J. The dike contained some curious sphe- 

 roids that strongly suggested leucite, but which were altered 

 in every case to a mass of analcite, calcite, and feldspar. From 

 this it was concluded that fresh material would be necessary to 

 decide the presence of this rare and interesting mineral, 

 although the nearness of the elaeolite-syenite at Beemerville, 

 gave additional reason to suspect it. The past summer, being 

 again in the region, the writer visited the extensive quarries 

 for limestone, that have been opened up at Rudeville, which 

 is over on the opposite side of an Archsean ridge (Hamburg- 

 Mountain), from Hamburg and the first mentioned dike. The 

 white crystalline limestone is cut by a dike about 12 feet wide, 



*This Journal, III, xvi, p. 42, 1878. 



Am. Jour. Sci— Third Series, Vol. XLVII, No. 281.— May, 1894. 

 23 



