186 G. H. Williams — Celestite from West Virginia. 



In nearly all cases the predominating form is the brachypyra- 

 mid, <p, 1*3 (133). Such, for instance, are the crystals called 

 by Haiiy "apotome" from the marl of Montmatre and Bougi- 

 val near Paris ;* and those designated as " dioxynite " from 

 Meudon in the same region. f Similar crystals of celestite are 

 also described by Sucrow;}: and Schmid§ from the Muschelkalk 

 of Dornburg near Jena ; by von Lasaulx from Girghenti on. 

 Sicily ;|| and by Groth from Hall in the Tyrol.^f 



The brachypyramid, #, P\ (144) was first mentioned by 

 Brooke and Miller.** It has since been recognized by Auer- 

 bach on crystals from Dornburg, and Montecchio in Yicentia ;ff 

 by Groth on those from Pschow in Silesia \%% and by von Hauer 

 on those from the Banat.§§ 



This pyramid was, however, first noticed as predominating 

 and giving the habit to celestite crystals by von Lasaulx in 

 1879. II This author describes an occurrence of this mineral in 

 the marl of Yille-sur-Saulx, Dept. Haute Marne, France, which 

 must bear a close resemblance to that in Mineral Co., W. Va. 

 At least this would appear to be the case from the published 

 descriptions, since I have had no opportunity to examine speci- 

 mens from this locality. 



In passing, it may also be not without interest to refer to 

 the pyramidal crystals of Hungarian anglesite figured by 

 Krenner.1[Tf These often have a habit closely like that of the 

 above-mentioned celestites, but their predominating pyramid 

 is 7T, Ps (155V ^ 



The West Virginia celestite crystals acquire additional inter- 

 est from their strong resemblance, in form as well as in their 

 surface markings, to the well-known Sangerhausen pseudo- 

 morphs, whose further resemblance to the "thinolite" of the 

 desiccated lake-basins of the west has been pointed out by 

 Clarence King, and E. S. Dana.*"** The Sangerhausen pseudo- 

 morphs have generally been referred to gaylussite, but Descloi- 

 zeaux unqualifiedly identifies them with the variety of celestite 



* Traite de Mineralogie, 2d ed., 1882, vol. ii, p. 33. Atlas, PI. xliii, fig. 81. 



f Ibid., p. 35. Atlas, pi. xliv, fig. 85. Of. Schraufs Atlas der Krystalformen, 

 VLieferung, 1876. 



+ Pogg. Ann., vol. xxix, p. 504. pi. i, fig. 16, 1833. 



§ Ibid., vol. cxx, p. 637, 1863. ' 



|| Neues Jahrbuch fur Min., etc., 1879, p. 509. 



\ Mineraliensammlung der Universitat Strassburg, 1878, p. 146. 



** Mineralogy, 1852, p. 527. 



\\ Sitzungb. Wien. Akad., vol. lix, pp. 580 and 588. 1869. 



\\ Mineraliensammlung der Universitat Strassburg, 1878, p. 146. 



§§ Verhandl. k.k. geol. Reichsanstalt, 1879, p. 216. Cf. Zeitschr. fur Kryst., 

 vol. iv, p. 634. 



HI Sitzungsber. der schlesischen Gesellschaft fur vaterlandische Cultur, Nov. 19,. 

 1879. Cf. Zeitschr. fur Kryst., vol vi, p. 203. 



^ Zeitschr. fur Kryst, vol. i, pi. xv, 1877. 



*** A Crystallographic Study of the Thinolite of Lake Lahontan. Bull. U. S- 

 Geol. Survey, No. 12, 1884. 



