Standard X-ray Diffraction Powder Patterns

Arsenic Trioxide, claudetite, As2O3 (monoclinic)Powder data cards. None.Additional published patterns. None.NBS sample. The sample of claudetite wasobtained from the National Museum, No. 1737from the San Domingo mines, Portugal. Spectrographicanalysis showed the following major impurities: 0.1 to 1,0 percent each of aluminum,yttrium, and zinc; 0.01 to 0.1 percent each ofbarium, calcium, cobalt, chromium, iron, magnesium, titanium, and tungsten.The sample was colorless. Due to the highindices of refraction a complete optical analysiswas not obtained, but partial results seemed toconfirm the data given in Dana [4].The ^-values of the three strongest lines are:3.245, 3.454, and 2.771 . AStructural data. Buerger [1] in 1942 determinedthat claudetite has the space group C|h-P2i/n(No. 14) and 4(As2O3) per unit cell.The density of claudetite calculated from theNBS lattice constants is 4.186 g/cm 3 at 25 C.References[1] M. J. Buerger, The unit cell and space group of claudetite, As2O3, Am. Mineralogist 27, 216 (1942).[ 2] K. A. Becker, K. Plieth, and I. N. Stranski, Strukturuntersuchungder monoklinen ArsenikmodifikationClaudetit, Z. anorg. allgem. Chem. 266, 293-301(1951).[3] A. J. Frueh, The crystal structure of claudetite (monoclinicAs 2O3) Am. Mineralogist 36, 833-850 (1951).[4] Palache, Berman, and Frondel, Dana's System ofMineralogy, 7th Ed. 1, 546 (1951).hkl020110Oil120021T01Til130101040031140131, 041210211, 150002051012221, T51151112, 160042T42251, 170071T71080152, 261180T13123532, 091182213163572,0-11.1Internal StandardSilver, a=4.0861 ACu, 1.5405 1 at 25 CdA6. 4964. 9244.2774. 1183.7173. 5863.4543.3563. 3283. 2453. 1292.7712. 6402.6082,3332. 2642. 2532. 2312. 1042.0482.0051.8571.7881, 75141, 71631. 64771. 62281. 59881. 55221. 47161. 39151. 37491. 29371. 26671. 22201. 1423792649