W, F. Hillebrand — Vanadium Sulphide, Paironite. 141 



Art. XIII. — The Vanadium Sulphide, Patronite, and its 

 Mineral Associates from Minasragra, Peril • by W. F. 

 Hillebrand. 



In the Engineering and Mining Journal, Sept. 1, 1906, 

 p. 885, and in Inform aciones y Memorias of the Society of 

 Engineers of Lima, Peru, vol. viii, pp. 171-185, 1906, two 

 accounts are given by Foster Hewett and Jose J. Bravo, 

 respectively, of a remarkable vanadium occurrence at Minas- 

 ragra, about 46 kilometers from Cerro de Pasco in Peru and 43 

 from the railway. The two accounts agree in all essential 

 points that are common to both, though that of the Peruvian 

 writer is much the more detailed as to the geography and geol- 

 ogy of the region. The data immediately following are drawn 

 from the publications referred to, and from additional infor- 

 mation furnished by Mr. Hewett. 



.Cretaceous sedimentaries — shales, sandstones and limestones 

 — dipping at about 45° have been intruded by two (Hewett) 

 or three (Bravo) series of eruptive dikes, and at the point of 

 greatest frequency of these intrusives occurs the vanadiferous 

 deposit, which had as yet been opened up only very superfi- 

 cially by a few pits along an extension of 400 feet on the 

 outcrop. The vanadiferous materials occur in vein formation 

 and are three in kind, aside from alteration products that cover 

 the surrounding surface. Under the hanging wall is a thick- 

 ness of about eight feet of an amorphous material of complex 

 mineral composition which will be designated hereinafter as the 

 " ore." Its color is dark, almost black (dark green like oliven- 

 ite, according to Hewett, bright lead-gray with metallic luster 

 on fresh surfaces but soon tarnishing, according to Bravo). 

 Adjoining this material, without distinct line of demarkation 

 beneath, is a singular hard coke-like carbonaceous matter, from 

 eight inches to two feet in thickness, which blends on the far- 

 ther side into a lustrous black substance of from four to six 

 feet thickness, designated as asphaltite by both the above 

 named writers, although it is a sulphur compound of carbon 

 with very little hydrogen. 



These three substances will now be considered in detail, 

 beginning with the last, which from its unique position among 

 carbonaceous mineral substances seems worthy of a specific 

 name for the purpose of more ready separation from those 

 bitumens and coals which it so strongly resembles in its super- 

 ficial aspects. The name quisqueite is suggested by Mr. 

 Hewett, after the settlement nearest to the locality of occur- 

 rence. The materials described in the following pages were 



Am. Jour. Sci. — Fourth Series, Vol. XXIV, No. 140. — August, 1907. 

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