EOGERS : LIST OF MINERALS FOUND IN JOPLIN DISTRICT. 165 



dence that the cuprite has been derived from any preexisting mineral, 

 as far as the examination of the specimens shows. 



Gypsum. Crystals of this mineral are found in bituminous shale, 

 probably of Coal Measure age, on the Mastin ground, southwest of 

 Galena ; also of recent origin, coating the chert in old dump piles. 



Hematite. Occurs as a thin, black, botryoidal incrustation and 

 soft red stain on chert in Cooper Hollow, Galena. 



Kaolinite. Found as a thin white coating on micaceous shale at 

 Cave Springs, Mo.; also as powder in cavities in chert at the "Tree 

 Toad" mine. 



Linarite. A mineral answering the tests of linarite was found in 

 very small quantities at Galena. It is azure-blue in color, with vitre- 

 ous luster, and reacts for lead, copper, and sulfuric acid ; gives off 

 water and loses its color when heated in closed tube ; soluble in nitric 

 acid, leaving a white residue of lead sulfate. It is associated with 

 cerussite and malachite as a thin layer between them. Linarite seems 

 to have been reported from but two other localities in this country — 

 at the Cerro Gordo mines, Inyo county, California, and Organ moun- 

 tains, near Las Cruces, N. M. 



2fuscovite. Occurs as crystalline scales in shale at the Cave Springs 

 mines and is no doubt of secondary origin. 



Pyrolusite. A soft, black mineral from a shaft west of "Black 

 Hill," in the western part of Galena, is probably pyrolusite. It has a 

 botryoidal surface ; the streak is black with submetallic luster. Re- 

 acts for manganese and in the closed tube gives off' a small amount of 

 water, as pyrolusite often does. Dendritic markings on the chert at 

 Granby may probably be referred to this mineral. 



Sulfur. This mineral was found as minute crystals and as a thin 

 crystalline coating on cleavage surfaces of galena. Galena in de- 

 comiDosing ordinarily gives rise to the carbonate, cerussite, passing 

 perhaps through the intermediate stage of the sulfate, the sulfur be- 

 ing oxidized. The sulfur in the occurrence here described was not 

 oxidized, but set free, remaining as the native element. Sulfur was 

 also observed in cavities in sphalerite, as before in very small quan- 

 tities. Both the galena and sphalerite thus associated are from the 

 Bonanza" ground, northwest of Galena. As far as can be learned, 

 this is the first notice of native sulfur derived from sphalerite. 



MiNEKALOGICAL LABORATORY, UNIVERSITY OF KANSAS, MaT 1, 1900. 



