JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. 11 January 10, 1921 . No. 2 



MINERALOGY. — Bemeniite and neotocite from western Washington, 

 with conclusions as to the identity of bementite and caryopilite} 

 J. T. Pardee, E. S. Larsen, Jr., and George Steiger, U. S. 

 Geological Survey. 



Occurrence and association. 

 Specimens representative of manganese-bearing deposits in western 

 Washington collected in 191 7 and 191 8 by J. T. Pardee and examined 

 microscopically and chemically by Messrs. Larsen and Steiger, respec- 

 tively, are determined to be chiefly bementite, a hydrated silicate of 

 manganese. The material was collected at the Black and White, Apex, 

 Triple Trip and other mines and prospects along the north and south 

 forks of Skokomish River, Mason County, Washington, and from A. V. 

 Ginnett's prospect on Fidalgo Island south of Anacortes. Similar 

 material was found by Prof. Henry Landes at the Tubal Cain mine 

 west of Quilcene and is reported by others to occur on the mainland 

 about 10 miles northeast of Anacortes and at a locality a few miles 

 south of Lake Queniault. Most of these occurrences are within a 

 narrow belt about 70 miles long that extends from the vicinity of Lake 

 Queniault northeastward into the drainage area of Dungeness River 

 and covers part of the eastern slope of the Olympic Mountains. The 

 remainder, comprising the deposits near Anacortes, are about 60 miles 

 further northeastward. This rather extensive occurrence of bementite 

 in Washington is interesting in view of the fact that so far as known 

 that mineral is rare elsewhere. Dana- mentions only one locality of 

 its occurrence in America, namely, Franklin Furnace, New Jersey. 



1 Published by permission of the Director of the U. S. Geological Survey. Received 

 November 26, 1 920. 



- A system of mineralogy, ed. G, p. 704, 1914; third appendix to same, p. 12, 1915. 



25 



