• Downeyite Mineral Data

    webmineral.com/data/Downeyite.shtml Downeyite Crystallography: Axial Ratios: a:c = 1:0.60645 : Cell Dimensions: a = 8.36, c = 5.07, Z = 8; V = 354.34 Den(Calc)= 4.16 : Crystal System:
  • Downeyite dictionary definition | downeyite defined

    www.yourdictionary.com/downeyite downeyite definition: Noun 1. (mineralogy) A tetragonal-ditetragonal dipyramidal colorless mineral containing oxygen and selenium.Origin -ite...
  • What does downeyite mean? - Definitions.net

    www.definitions.net/definition/downeyite Definition of downeyite in the Definitions.net dictionary. Meaning of downeyite. What does downeyite mean? Information and translations of downeyite in the most comprehensive dictionary definitions resource on the web.
  • Downeyite Mineral Data - webmin.mindat.org

    webmin.mindat.org/data/Downeyite.shtml Downeyite Classification: Dana Class: Simple Oxides : with a cation charge of 4+ (A++++ O2) Dana Group : Downeyite SeO2 P 4/mbc 4/m 2/m 2/m : Paratellurite TeO2 P 4 1 2 1 2,P 4 3 2 1 2 4 2 2 : Strunz Class: 04.DE.05 ...
  • downeyite - Wiktionary

    en.wiktionary.org/wiki/downeyite downeyite A tetragonal-ditetragonal dipyramidal colorless mineral containing oxygen and selenium. References “Downeyite ...
  • Downeyite, the first verified natural occurrence of SeO2 ...

    pubs.geoscienceworld.org/.../Downeyite-the-first-verified-natural-occurrence-of Downeyite, naturally occurring SeO 2, forms as acicular crystals from gases escaping through vents on culm banks in the anthracite region of Pennsylvania.This exceedingly hygroscopic mineral forms at temperatures of about 200°C in the vicinity of the vents; it is associated with elemental selenium, monoclinic sulfur, mascagnite, and anhydrous ammonium aluminum sulfate.
  • Downeyite SeO2 - Handbook of Mineralogy

    www.handbookofmineralogy.com/pdfs/downeyite.pdf Downeyite SeO2 c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Tetragonal. Point Group: 4/m2/m2/m. As acute needlelike crystals, up to 2 cm in length, elongated along [001]; also as radiating sprays.
  • Selenium dioxide - Wikipedia

    en.wikipedia.org/wiki/Selenium_dioxide The natural form of selenium dioxide, downeyite, is a very rare mineral. It is found in only a very few burning coal dumps. Uses Organic synthesis. SeO 2 is an important reagent in organic synthesis. Oxidation of paraldehyde (acetaldehyde trimer) with SeO 2 gives glyoxal and the oxidation of cyclohexanone gives cyclohexane-1,2-dione.
  • (PDF) Downeyite, the first verified natural occurrence of SeO2

    www.researchgate.net/.../290807802_Downeyite_the_first_verified_natural_occur... PDF | On Jan 1, 1977, R.B. Finkelman and others published Downeyite, the first verified natural occurrence of SeO2 | Find, read and cite all the research you need on ResearchGate
  • Minerals, Metals, and Gemstones of Pennsylvania | HubPages

    hubpages.com/games-hobbies/Minerals-Metals-and-Gemstones-of-Pennsylvania Downeyite. Downeyite is a mineral that is primarily comprised of the element selenium. Downeyite crystals are colorless and transparent and have a diamond-like luster. Eastonite. Eastonite is a mineral of the biotite subgroup of mica. Its colors are typically towards the lighter shades of dark mica. Fayalite