00000nam 2200000za 4500 9.840625 CaOODSP 20221107151905 cr ||||||||||| 170728s1968 oncad ob f000 0 eng d CaOODSP eng n-cn--- M38-8/75E-PDF M38-8/75 Faye, G. H. The origin of pleochroism in erythrite [electronic resource] / G.H. Faye and E.H. Nickel, Mineral Sciences Division. Ottawa : Queen's Printer, 1968. p. [493]-504 : charts, ill. Reprint series ; RS 75 Cover title. "Reprinted from The Canadian Mineralogist, pp. 493-504, Vol. 9, Pt. 4, 1968." Historical publication digitized from print 2017 [by Natural Resources Canada]. Includes bibliographical references. "Optical absorption measurements show that the pleochroism of erythrite is due to variations in the main absorption envelope in the 400 to 600-mμ region as crystallographically oriented sections are rotated in linearly polarized light. The absorption envelope arises from the 4T1 (F) → 4T1 (P) transition, with contributions from transitions derived from 2G and 2H levels, in octahedrally coordinated Co2+ ions, of which there are two kinds (CoI and CoII) in erythrite. The pleochroism is related to the interaction of the electric vector of light with electrons located in specific t2g orbital lobes of ions in the CoI and CoII sites. The validity of the present interpretation rests on the assumptions that erythrite is isostructural with vivianite and symplesite and that the principal optical directions are essentially coincident with the "molecular axes" of the Co2+-bearing octahedra"--Abstract, p. [493]. gccst Minerals Nickel, Ernest H., 1925- Canada. Natural Resources Canada. Canada. Department of Energy, Mines and Resources. Canada. Mines Branch. Reprint series - Dept. of Energy, Mines and Resources, Mines Branch ; RS 75 (CaOODSP)9.834843 PDF 4.62 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M38-8/M38-8-75-eng.pdf 300154