Moses — Mineralogical Notes. 99 



The examination suggests very definitely mercuric iodide in 

 isometric crystals of the hexoctahedral (holohedral) class. 

 The tetrahedral copper iodide, marshite, and the hexagonal 

 silver iodide iodyrite* both occur at the Broken Hill Mines, 

 and Mr. George Smith mentionsf " iodyrite associated with a 

 bright red mineral readily tarnishing on exposure and found to 

 be sulphide of mercury." The specimen examined has been 

 in my possession over a year and has not noticeably tarnished, 

 but as the Castillos mineral coccinite is said to change on ex- 

 posure, it may be that the supposed sulphide of mercury will 

 prove to be the mercuric iodide here described. 



The two descriptions of "coccinite," the Mexican iodide of 

 mercury, differ notably from this material. That of Castillosf 

 from Zimapan and Culebras is " in acute acicular rhombic pyra- 

 mids 2-6 mm long, fine red to yellow, changing to greenish gray 

 and dark green on exposure; transparent to translucent. In 

 closed tube a sublimate of Hg 2 CI 2 , white when cold and leav- 

 ing residuum dull red hot, orange yellow cold and before blow- 

 pipe turns aurora red and disappears with odor like selenium." 



The older description by Del Rio in 1828 of material from 

 Casas Viejas, Mexico, describes particles of reddish brown 

 color, deeper red than cinnabar, on selenide of mercury, and 

 adamantine in luster. Castillos says the specimens labelled by 

 Del Rio contained no iodine. 



It does not seem that the name coccinite can be at once 

 applicable to the acute rhombic pyramids of Castillos and the 

 cubes from Broken Hill Mines, and it is hoped that more 

 material may be found for further examination. 



(2) New Forms on Bergen Hill Pectolite. 



Mr. F. V. Cruser, student in chemistry at Columbia Univer- 

 sity, found crystallized pectolite in an abandoned quarry at 

 Weehawken, N. J., not far from the 42d Street Ferry. The 

 crystals are needles about 3 mm long by only 3/10 mtn broad, but 

 fair reflections were obtained from two of the crystals by use 

 I of the Goldschmidt two-cir- 



cle goniometer. The crys- 



-^____^jy^___- ZF^^i ^ 8 were mounted with the 



" —TTTrrr: "_ _"_"__" z^zz^X- - \ k axis b normal to the vertical 



— ~~~^ w __ll^^ v;: ^bJ c i rc ^ e an d the results later 



transposed to conform to the 

 conventional position with the axis b normal to the vertical 

 circle. 



As in previously recorded measurements the faces a (100) 



* Proceedings Royal Society New South Wales, xxvi, 326 and 371, 1892; xxvii, 

 366. 1893: xxix, 49 and 189, 1895. flbid., xxvii, 372. 



% Dana's System, 6th Ed., 161. 



