Kristallform und Kristallelemente des Walpurgins

Systematic mineralogy of uranium and thorium

“…The elements used to .·calculate the tabl~ are those of the X-ray unit cell obtained by by the precession method on the material of analysis ·3. The relations of this cell to the morphological cells used earlier by E. Fischer (1945Fischer ( , 1948 and by Weisbach (1877) are ambiguous and have been discussed by but are probably low owing to inclusions and porosity in the samples. ~rhe specific gravity decreases with increasing substitution of P for As.…”

“…The twinned crystals commonly are attached by one end of the c-axis, and have an oblique termination on the free end, givinJ!~ a pseudo-monoclinic, gypsumlike appearance. A typical crystal is shown in figure 17 and additional drawings are given by , V. Goldschmidt (1913-23), and E. Fischer (1945Fischer ( , 1948.…”

Raman spectroscopy of walpurgite

“…1,2 It is a hydrated bismuth uranyl arsenate oxide of high density, 5.95-6.9. The mineral is often associated with other uranium minerals including bismutite, torbernite, zeunerite, uraninite, and other uranium minerals.…”

“…2). 2,5,6 Orthowalpurgite (space group Pbcm, no. 57) is a polymorph of walpurgite 5 and there is also one phosphate analog.…”