450 DESCRIPTIVE MINERALOGY. 



CUMMINGTONITE.* 



Colour greyish white. In fine needles and tufts of imperfect crystals. Lustre silky- 

 Opaque. Hardness 6.5. Sp. gr. 3.20. Infusible before the blowpipe. Composed of silica 

 56.54, protoxide of iron 2 1.67, protoxide of manganese 7.80, soda 8.44, volatile matter 3.18. 



Cummington and Plainfield in Massachusetts. 



■'O" 



DANBURITE.t 



Colour shades of honey-ycUow. Crystallized. Primary an oblique rhombic prism. Lustre 

 highly vitreous. Transparent. Hardness 7.5. Sp. gr. 2.83. Phosphoresces before the 

 blowpipe, and fuses into a white blebby transparent glass. Composed of silica 56.00, lime 

 28.33, alumina 1.70, yttria ? 0.85, potassa (with soda?) and loss 5. 12, water 8.00. 



Danbur)^, Connecticut. 



DYSLUITE4 



Colour yellowish or greyish brown. Crystallized. Primary the regular octahedron. Lus- 

 tre vitreous, inclining to resinous. Nearly or quite opaque. Hardness 7.05. Sp. gr. 4.55. 

 Before the blowpipe, it assumes a red colour, but does not melt. Composed of alumina 

 30.49, oxide of zinc 16.80, peroxide of iron 41 .93, protoxide of manganese 7.60, silica 2.97. 



Sterling, New-Jersey, with franklinite and troostite. It has been thought to be identical 

 with automalite. 



ELECTRIC CALAMINE. 



Siliceous Oxide of Zinc. Ckavcland. 



Colour usually white or yellow. Crystallized and massive. Primary a right rhombic 

 prism. M on M' 108° 40'. Lustre vitreous. Transparent to opaque. Hardness 5.0. 

 Sp. gi-. 3.30 to 3.60. Infusible before the blowpipe. Composed of oxide of zinc 66.83, 

 silica 24.89, water 7.46. 



Jefferson county, Missouri, with galena and other lead ores. 



EREMITE.§ 



Colour between clove and yellowish brown. Crystallized. Primary a right oblique angled 

 prism. M on T 140=^ 30'. Lustre resinous to vitreous. Semi-transparent. Hardness 5.0 

 to 5.5. Sp. gr. 3.71. Infusible by the blowpipe, but becomes transparent and colourless. 



Watertovvn, Connecticut, in a bowlder of albitic granite. 



* Thomson. Outanrs of Mineralogy, Sfc. % Thomson. Outlines of Mineralogy, J^-c. 



i Shepard. American Jmrnil of Science. XXXV. 137. ^ Shepard. American Journal of Science. XXXII. 341. 



