RAnsome.] GANGUE MINERALS. 73 
RhodochrosUe.—MnC0 3 . Rhombohedral. Massive or in small 
rhombohedra in vugs. Cleavage like calcite. Usually some shade of 
pink. Hardness, 3.5-4.5. Specific gravity, 3.5. Effervesces freely 
in powdered form with dilute acid. 
Occurs abundantly in massive form as gangue in the Titusville 
lode, and in small amounts in the veins of the Empire group on Sultan 
Mountain, and in most of the lodes in the northeast quarter of the 
quadrangle, where it may usually be observed as minute rhom- 
bohedral crystals lining small vugs. In small quantity it always 
occurs in the veins containing rhodonite. In the Golden Fleece vein 
it forms, with quartz, the gangue of the rich free-gold ore, and also 
occurs in small amount in the Camp Bird lode. It is found in beauti- 
fully colored rhombohedral crystals in the Grizzly Bear mine on Bear 
Creek, jusl within the northern boundary of the quadrangle. 
Kctolinite. — K 4 Al 2 Si 2 9 . Monoclinic. Massive, or in a loose pow- 
der consisting of microscopic crystalline scales. White. Hardness, 
2-2.5. Specific gravity, 2.6. Can be scratched with the fingernail. 
Sniool h to the touch. 
This mineral occurs in very pure form in the National Belle mine 
as a snowy white powder, made up of minute crystalline scales. As 
seen in the upper workings in 1899 it occurs filling fissures in the 
country rock or as a filling between the fragments of brecciated zones 
near the ore bodies. It was apparently in these cases deposited later 
than the ores, partly taking the place in this mine of the clay gouge 
commonly associated with post-mineral movement in other localities. 
As an original constituent accompanying 1 lie ores, kaolin occurs 
abundantly in the stock deposits of the Red Mountain district, as 
shown by the materials now visible on their dumps. This is usually 
a firm, compact variety, intimately associated with pyrite. A char- 
acteristic form is that in which the kaolin is traversed by numerous 
anastomosing veinlets of pyrite, giving it a spotted and sometimes a 
schistose appearance (fig. 6). It was not possible to investigate the 
occurrence of kaolin in any of the deeper workings of the Red Moun- 
tain mines, but from what could be seen it appears to have accom- 
panied the ores to the greatest depths there attained — about 1,300 
feet. It was evidently derived from the country rock adjacent to the 
ore bodies as a product of its alteration by the thermal waters. 
In the Zuni mine, on Anvil Mountain, compact kaolinite is abun- 
dant and is directly associated with pyrite, barite, and small nests of 
enargite to form the lower exposed portion of the ore bod}^. The 
pyrite is often beautifully crystallized in very slightly modified octa- 
hedra, which are thickly embedded in the white kaolinite. 
As a soft white powder kaolinite occurs with the gold quartz of 
the Tomboy and Camp Bird mines. In the Tomboy the kaolin is 
sometimes mixed with sericite. 1 
1 Purington, loc. cit.,p.840. 
