ROGERS: LIST OF MINERALS FOUND IN JOPLIN DISTRICT. 163 



29. Marcas'tte. Twins are abundant, among them cyclic fivelings. 



30. Melanterite. Wliite crystalline jDowder i)roducecl by the oxi- 

 dation of pyrite or marcasite. 



31. Mlmetlte. Reported by Dr. W. P. Jenney as a thin crystal- 

 line coating on galena, at Seneca, Newton county, Missouri. 



32. 2fuscovite.\ 



33. Opal, var. Tripoli, as extensive beds of soft, massive, white to 

 buff-colored material. 



34. Pf/rite. Quite common, but not as abundant as marcasite. 



35. Pyroluslte.j 



36. Puromorphife.X Small grass-green prismatic crystals and 

 coating on chert. Found at Granby, Joplin, and Galena. At Granby 

 it is pseudomorphous after galena. 



37. Quartz. The crystals are usually very small, but some from 

 Granby and Wentworth measure two and one-half cms. in the direc- 

 tion of the vertical axis. 



38. S)nlthsonife. In small crystals, with rounded faces, but more 

 often as stalactitic and botryoidal forms ; also pseudomorphous after 

 calcite and dolomite, especially at Granby. 



39. Sp/)aler/fe. A white amorphous of zinc sulfid was described 

 by Robertson,* from Galena and near Joplin. 



40. Sulfa /'.J 



— . Trijjoll. See Opal. 



41. Yivianlte. Reported by Dr. G. Hambach as blue, earthy pow- 

 der from Joplin. 



42. Wavellite. Reported by Dr. G. C. Broadhead as small, white, 

 radiating crystals on chert from Jasper county. 



43. Warfsite. Small hexagonal crystals on stalactitic sphalerite, 

 at Joplin. By whom first found is not known by the writer. 



44. C7ialcaaf/iffe. The writer has recently found this mineral at 

 the Irene Mining Company's mine, in Em^Dire City, Cherokee county, 



1 Kansas. It occurs as small blue columnar crystals, associated with 

 I sphalerite, pyrite, and chalcopyrite, and is doubtless the result of the 

 I oxidation of the latter. The specimens were found on the dump 

 ( piles, but the miners say that the mineral is frequently observed on. 

 ( material just after it is hoisted from the shaft. 



; Allopliane ? A hydrous aluminium silicate related to allophane in 

 j composition occurs at the "Big Coon" mine and at the mine of the 

 l Dearborn Mining Company, at Galena, Kan. The mineral appears as 

 a thin incrustation, often with a botryoidal surface, associated with 

 sphalerite, chert, and a soft, clay-like material. It is amorphous, col- 

 orless to light brown or green, subtranslucent to translucent, with res- 



*Amer. Journ. Soc, vol. XL (3), pp. 160, 161, 1890. 

 12— K.U.Qr. A— ix 2 



