W. Lindgren, etc. — A Neiv Mineral. 195 



Art. XVI. — Melanovanadite } a Neiv Mineral from Mina 

 Ragra, Pasco, Peru; by Waldemar Lindgren, L. F. 

 Hamilton and Charles Palache. 



Introduction. — Late in 1920 Mr. "W. Spencer Hutch- 

 inson, consulting engineer for the Vanadium Corpora- 

 tion of America, brought to the attention of the senior 

 author three specimens of a mineral collected by him at 

 Mina Eagra, Peru. He suspected that it was a new min- 

 eral, and this opinion was proved correct by chemical and 

 optical examination. The formula appears to be 2CaO. 

 2V 2 4 .3V 2 5 and the name of Melanovanadite is proposed 

 for it, in allusion to it being practically the only vanadium 

 mineral of a deep black color. x 



Description. — The mineral was collected from No. 1 

 tunnel in the lower part of the great patronite deposit 

 at Mina Ragra, below the strongly oxidized zone and 

 90 feet below the surface. This tunnel extended out 

 into the surrounding black shale from the so-called 

 Veta Madre, or main, lower section of the deposit. Mr. 

 Hutchinson believes that the ore is not conformable with 

 the dip of the slates but forms a crosscutting body. The 

 mineral occurred along fractures in the shale, not far 

 from the main body, and there was enough of it to be 

 mined as rather high-grade vanadium ore. One of the 

 specimens showed a compact brownish gray shale rich in 

 gypsum. On a joint plane were flat radial or divergent 

 aggregates of a black lustrous mineral of prismatic habit 

 and near these the shale was blackened. 



The best specimen, about 12 by 8 by 6 cm., is composed 

 of a soft porous black material evidently altered shale 

 traversed by brecciated openings or fractures coated by 

 closely massed divergent and velvety bunches of small 

 acicular black crystals, with a maximum length of 3 or 4 

 mm. These bunches are easily removed and a quantity 

 of about 2 grams was obtained which, for purposes of 

 analysis, was hand-picked under the binocular micro- 

 scope. The product was almost pure, containing only 

 a few particles of altered shale and of pascoite. Regard- 

 ing the paragenesis and the nature of the altered shale 

 see below. 



1 The ending "vanadite" is an obsolete form of " vanadinite, " but 

 there can scarcely be any objection to using this form in the present case. 



