226 MINEKALOGT. 



Cohen, E. [Microscopical Inclosures in South African Diamonds.] 

 Natarforscher, November. 



. IJeber Einschliisse in sudafrikanischen Diamanten. [En- 

 closures in S. African Diamonds.] N. Jahrb. Heft vii. pp. 752, 

 753. 

 Finds that some of the specks in diamonds, taken for carbon, consist 

 of iron-glance, in some cases showing crystalline forms. Concludes 

 that most, if not all, the specks are due to this mineral. F. W. R. 



Cossa, Prof. A. Sulla predazzite periclasifera del Monte Somma. 

 [Periclase-Predazzite of Monte Somma.] Pp. 8. 4to. Borne, 



Dana, E. S. Mineralogical Notes. — No. i. On the Optical Character 

 of the Chondrodite of the Tilly Foster Mine, Brewster, New York. 

 Amer. Journ. ser. 3, vol. xi. pp. 139, 140. 

 Repeated measurements, of which particulars are given, confirm the 

 results, before obtained, that chondrodite crystals of the second type 

 belong optically to the monoclinic system. A crystal of the third type 

 has been examined, and is also shown to be at variance with the sup- 

 posed orthorhombic character of the species. G. A. L. 



. Mineralogical. Notes. — No. ii. On the Samarskite of Mitchell 



County, North Carolina. Arner, Journ. ser. 3, vol. xi. pp. 201- 

 204 ; figs, in text. 



This niineral is found in the mica mines of this region, which are 

 worked in granite-veins intersecting gneiss and mica-slate. Other 

 localities are given. The associated species are columbite, another 

 mineral of this tantalic group closely allied to pyrochlore and to micro- 

 lite, and a yellow mica. An analysis of samarskite, by Miss Ellen 

 Swallow, gives : — Metallic acids, tantalic group, 54-96 ; SnO^, 0-16 ; 

 UO, 9-91 ; FeO, 14*02 ; MnO, 0-91 ; CeO, 5-17 ; YO, 12-84 ; MgO, 0-52 ; 

 insol. 1-25. Full crystallographic characters are given. G. A. L. 



Mineralogical Notes. — No. iii. On new twins of Staurolite 



and Pyrrhotite. Amer. Journ. ser. 3, vol. xi. pp. 384-388. With 

 notes on the composition and mode of occurrence of the pyrrhotite 

 from Elizabeth town, Ontario, pp. 387, 388. Figures in text by 

 Dr. B. J. Harrington. 

 The twin Staurolites are from Cherokee County, N. Carolina, and 



Tannin County, Georgia. Analyses of the pyrrhotite are given by Dr. 



Harrington. G. A. L. 



On the Chondrodite from the Tilly-Foster Iron-mine, 



Brewster, New York. Trans. Conn. Ac. Sci. vol. iii. pt. 1 , pp. 67- 

 96, pis. xi.-xiii. 

 Noticed, from condensed account in Amer. Journ., in Geological 

 Record for 1875, p. 235. 



Danhree, Prof. Exemples de formation contemporaine de la Pyrite 



