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On the identity of Neocolemanite with Colemanite

Published online by Cambridge University Press:  14 March 2018

A. Hutchinson*
Affiliation:
University of Cambridge

Extract

The beautiful crystals of colemanite from the Death Valley, Inyo County, and from the Calico district, San Bernardino County, California, were described almost simulfmneously in the autumn of 1884 by several different observers, The most complete examination we owe to Jackson, who identified forty-forms and determined the axial ratios which are usually accepted for the mineral, namely, a : b : c = 0.774843 : 1 : 0.540998 : β = 110° 9′ 15′′. Very similar values for these constants were adopted by Hiortdahl and by vom Rath.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1912

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References

Page 239 note 1 Jackson, A. W., Bull. Calif. Acad. Sciences, 1885, No. 2, pp. 286 Google Scholar, and 1886, No. 4, 858-865 ; Hiortdahl, T., Zeits. Kryst. Min., 1885, vol. x, pp. 2581 Google Scholar ; C. Bodewig and G. vom Rath, ibid., pp. 179-186; A. Arzrnni, ibid., 272-276.

Page 239 note 2 Eakle, A. S., Univ. Calif. Publ. Bull. Dept. Geol., 1902, vol. iii, pp. 3149 Google Scholar.

Page 239 note 3 All the angles of colemanite quoted in this paper have been computed from these constants.

Page 239 note 4 Eakle, A. S., ‘Neocolemanite, a variety of colemanite, and howlite from Lang, Los Angeles County, California,’ Univ. Calif. Publ. Bull. Dept. Geol., 1911, vol. vi, pp. 179189 Google Scholar.

Page 242 note 1 The stereograms, figs. 1 and 2, are on the same scale and have been reduced from accurate projections 20 cm. in diameter. Since the plane of projection is the plane of symmetry, each dot may be taken to represent two faces, one in the northern hemisphere and one vertically below it in the southern.

A correction has been issued for this article: