Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-09T20:39:03.500Z Has data issue: false hasContentIssue false

Cassiterite pseudomorphs from Bolivia1

Published online by Cambridge University Press:  14 March 2018

Extract

One of the peculiarities of Bolivian tin-ores is the frequent occurrence of cindery and cellular masses of cassiterite, which is presumably of secondary origin. But, apart from impressions of quartz crystals, definite crystal-forms are rarely shown by this pseudomorphous cassiterite.

The pseudomorphs to be now described are from the Tres Cruces district, and were collected by my son, Mr. A. W. Pearce. The crystallographic determinations have been made by Mr. L. J. Spencer, and the specimens examined by him have been presented to the British Museum. The material consists of cavernous masses of dark brown, finely crystalline and granular cassiterite, associated with which is a pale yellow, ochreous substance.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1907

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

1

A preliminary account has appeared under the title : ‘Notes on the occurrence of pseudomorphs of oxide of tin after some unknown mineral from Bolivia,’ by R. Pearce : Trans. R. Geol. Soc. Cornwall, 1906, vol. xiii, pp. 150-2.

References

Page 345 note 2 Stelzner, A. W. (Zeits. Deutsch. geol. Ges., 1897, vol. xlix, p. 187)Google Scholar mentions cassiterite from Tasna with impressions of hexagonal prisms with basal plane, suggesting that, in this ease, the original mineral was apatite. On p. 134 he mentions tin-ore from Chorolque with impressions of an octahedral (?) mineral. Roberts, M. (Trans. Inst. Mining and Metallurgy, 1902-8, vol. xii, p. 404)Google Scholar also records the presence at Chorolque of sponge-like lumps of almost pure cassiterite with impressions of crystals. Finally, Domeyko, I. (Bull. Soc. Min. France, 1882, vol. v, p. 299)Google Scholar makes mention of impressions of apatite (?) crystals in massive eassiterite from Bolivia.

Page 345 note 3 Tres Cruces (Three Crosses) or, in the Indian language, Quimza Cruz, is a mountain in the province of Inquisivi, department of La Paz, and is situated about 85 miles NNW. of Oruro.