364 DESCRIPTIVE MINERALOGY. 



BUCHOLZITE. 



[In honor of Bucholz, a distinguished German chemist.] 



Bucholzitc. Ckavcland, Phillips and Shepard. — Bucholzite, or Anhydrous Silicate of Alumina. Thomson. — 

 Fibrolite. Mohs App. — Appendix to Sillimanite. Beudant. 



Description. Colour greyish white, with a very slight tinge of yellow. Structure fibrous. 

 The fibres are sometimes bent, and when viewed through a microscope, assume the appear- 

 ance of plates or imperfect prismatic crystals. Lustre silky. Hardness 6.0. Specific gravity 

 3.19. 



Composition. Specimen from Chester, Pennsylvania — Silica 46.40, alumina 52.92 

 {Thomson). 



From the Tyrolese Alps — Silica 46.00, alumina 50.00, protoxide of iron 2.50, potash 

 1.50 (Brandes). 



Both Beudant and Shepard seem to consider the sillimanite to be identical with bucholzite, 

 but the chemical composition of these two minerals is too widely dissimilar to admit such an 

 union. Further analyses, however, may remove this difficulty. I am more disposed to adopt 

 the views of Mohs in regard to the identity of fibrolite with bucholzite, as this, like the latter, 

 is a simple silicate of alumina, containing from 33 to 38 of silica and from 46 to 58 of alu 

 mina, with some iron. They also agree very well in their other characters. 



In the above description, I have followed Dr. Thomson, by whom it was drawn from the 

 fine specimens obtained at the locality in Chester, Penn. 



LOCALITIES. 



Orange County. This mineral occurs associated with quartz and mica, near the Queens- 

 bury forge in the town of Monroe. The fibres are straight or slightly contorted, of a white 

 or greyish white colour, and resinous lustre. They are very hard, but it is difficult to deter- 

 mine their crystalHne form. Specimens from this locahty exactly resemble those from Nor- 

 wich in Connecticut. 



According to Dr. Horton, there are several other localities in the same town. 



In Connecticut, bucholzite has been found at Humphreysville, while the variety or species 

 sillimanite occurs at Chester in the same State. 



