MnrERALOGT. 251 



SiLLiMAN, Prof. B. Tellurium Oree of Colorado. Amor. Journ. ser. 

 3, vol. viii. pp. 25-29 (with a note on the geology of the region 

 by A. 11. Marvine). 



The tellurium veins are on the sides of a porphyry dyke cutting 

 through metamorphic rocks at Gold Hill, near Denver City, and 8000 

 feet above the sea-level. Compared with the Transylvanian veins, the 

 phenomena are here remarkable for their simplicity : the only ores 

 noticed here are native tellurium, sylvanite, hessite, pyrites, zinc-blende, 

 chalcopyrite, and rarely galena; in the European locality they are 

 much more numerous. E. B. T. 



. Remarks on the Magnetites of Clifton, in St. Lawrence 



County, New York. Trans. Amer. Inst. Min. Eng. vol. i. pp. 364- 



371 (with discussion). 



The magnetites occur in Laurentian rocks, and are associated with 



calcite, hornblende, garnet, copper-pyrites, and magnetic pyrites. 



Analyses of the ores are given. F. W. R. 



. On the probable existence of Microscopic Diamonds, with 



Zircons and Topaz, in the Sands of Hydraulic Washings in Cali- 

 fornia. Trans. Amer. Inst. Min. Eng. vol. i. pp. 371-373. 

 Sands from workings at Cherokee, Butte Co., yielded hyacinths, topaz, 

 quartz, cliromic and titanic iron, with a few small masses supposed to 

 be diamond. F. W. R. 



Sipocz, L. Plagioklas von Yerespatak. Min. Mitt. Heft ii. p. 175. 



Analysis of plagioclase from Yerespatak in Transylvania. It is de- 

 scribed as an isomorphous mixture of two molecules of albite and three 

 of anorthite. F. W. R. 



. Zersetzter Plagioklas von Yerespatak. Min. Mitt. Heft ii. 



pp. 175, 176. 

 Analysis of an altered plagioclase from the quartz-andesite of Yeres- 

 patak. 



Sjogren, A. Ett par nya fyndorter for mineralet Manganofyll, 

 [New localities for Manganophyll.] Geol. fciren. Stockholm 

 Forhandl. bdt. i. p. 64. 



In addition to the old locality (Pajsberg mine) two new localities, 

 also in Wermland, are given, the Jacobsberg and LSngban mines. 



. Kort larobok i mineralogi for elementarloroverk. Andra 



upplagan. [Short text-book of- mineralogy. Ed. 2.] Falun. | 



Sket, W. On the mode of producing Auriferous Alloys by Wot 

 Processes. Chcm. News, vol. xxx. pp. 151, 152. 



Concludes that native alloys of gold and silver have been deposited 

 from alkaline solutions by the agency of metallic sulphides, such as 

 iron-pyrites. F. W. R. 



. Critical Notes upon the alleged nuclear Action of Gold upon 



