NEW MINERAL OCCURRENCES. 



1NESITE. 



SAN CAYETANO MINE NEAR VILLA CORONA, STATE OF DURANGO. MEXICO. 



MUSEUM No. M 5> 



A specimen of inesite from the above locality was first secured 

 by the writer in the spring of 1896 while at Villa Corona. Having 

 later determined the mineral by its blowpipe characters as inesite, 

 a request was sent to Mr. John D. Almy, one of the proprietors of 

 the mine, to procure more specimens if possible. Through his 

 kindness, and that of Mr. W. H. Schlemm, a few more specimens 

 were obtained, and were generously placed at the writer's disposal 

 for study. The rarity of the mineral makes the find of interest, as 

 it is known at only three other localities in the world, viz. : The 

 manganese mines at Nanzenbach, northeast of Dillenburg, Ger- 

 many; the Harstig mine, Pajsberg, Wermland, Sweden,* and 

 Jakobsberg, Nordmark, Sweden. t In the specimens from the San 

 Cayetano mine the mineral occurs partly in cavities and partly in- 

 tergrown with calcite and a flesh-colored manganesian calcite. 

 These fill narrow veins in what is probably an altered andesite. 

 The inesite occurs in tufts of radiating crystals which are of the 

 characteristic flesh-red color. The most characteristic pyrognostic 

 reaction of the mineral, noted by the writer, is, that when heated 

 in the closed tube it becomes opaque, gives off water, and falls 

 to powder. The crystals are of slender, prismatic habit, averaging 

 about 5 mm. in length. None were found doubly terminated, the 

 attachment at one end preventing the development of faces there. 

 A total of seven forms was identified, as follows: 



a (100), b (010), c (001), g (2oi), ' d (on), 



k (n. 0.12), and s (946). 



Of these the forms k (n. 0.12) and s (946) are new. The form/* 

 occurred on several crystals, the form s was found on but one. The 



♦Dana's Mineralogy. Sixth Edition, p. 564. 

 ••■First Appendix to Dana's Mineralogy. 1899. 



221 



