Osmiridium

Osmiridium, (and iridosmine) are names given to natural alloys of osmium and iridium, with traces of other platinum group metals. Osmiridium has been defined as containing a higher proportion of iridium, while iridosmine contains more osmium. However, as the content of the natural Os-Ir alloys varies considerably, the constituent percentages of specimens often reflects the reverse situation of osmiridium describing specimens containing a higher proportion of osmium and iridosmine containing more iridium. In 1963, M. H. Hey proposed using iridosmine for hexagonal specimens with 80%>Os>32%, osmiridium for cubic specimens with Os<32% and native osmium for specimens Os>80%. More recently, the Nomenclature Subcommittee of the Commission of New Minerals and Mineral Names, International Mineralogical Association has declared the mineral names osmiridium and iridosmine invalid and to be replaced by iridium and osmium, respectively. Other named naturally occurring alloys of platinum metals have included: iridrhodruthenium, platiniridium, ruthenosmiridium, and rutheniridosmine. The properties of these alloys generally fall between those of the members, but hardness is greater than the individual constituents.

Occurrence

Osmiridium is very rare, but it can be found in mines of other platinum group metals. One very productive mine operated at Lake Pedder near Tyenna in Tasmania during the Second World War with the ore shipped out by railway from Maydena. The site of the mine is now totally reclaimed by dense natural bush. It was once one of the world's major producers of this rare metal, and the osmiridium was mostly recovered found in shallow alluvial workings.^[1]

Isolation

It can be isolated by adding a piece to aqua regia, which has the ability to dissolve gold and platinum but not osmiridium. It occurs naturally as small, extremely hard, flat metallic grains with hexagonal crystal structure.

References

1. ^ Bottrill, R. S.; 1989, Economic Geology Appendix A; Tasmanian Geol. Surv. Explanatory Rept. 73 ( Huntley.) Cited at Adamsfield, Tasmania, Australia. Mindat.org. Accessed May 5, 2010.

• Osmiridium—Mindat.org

This article about a specific mineral or mineraloid is a stub. You can help Wikipedia by expanding it.v · Categories: Iridium compounds Native element minerals Osmium compounds Precious metal alloys Superhard materials Mineral stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем решить контрольную работу List of highways numbered 104 Cuisine of North Dakota Look at other dictionaries: Osmiridium — ist eine Platinmetall Legierung und Varietät des Iridiums, das als Mineral natürlich vorkommt. Osmiridium selbst ist von der International Mineralogical Association als Mineral nicht anerkannt (diskreditiert). Es enthält zusätzlich zu Iridium das …   Deutsch Wikipedia osmiridium — ● osmiridium nom masculin Synonyme de iridosmine. ● osmiridium (synonymes) nom masculin Synonymes : iridosmine …   Encyclopédie Universelle Osmiridium — Osmiridium, 1) (Osmium Iridium, Newjanskit, Lichtes O.), Mineral, erscheint meist in Körnern u. Blättchen, selten krystallisirt im hexagonalen System, Härte 7, specifisches Gewicht 19,3 bis 19,4, zinnweiß, enthält 49,33 Osmium, 46,71 Iridium,… …   Pierer's Universal-Lexikon Osmiridium — (Newjanskit), Mineral, s. Osmium …   Meyers Großes Konversations-Lexikon Osmiridium — Osmiridium,   ein Mineral, Iridosmium …   Universal-Lexikon osmiridium — [äs΄mə rid′ē əm, äz΄mə rid′ē əm] n. [ OSMIUM + IRIDIUM] IRIDOSMINE …   English World dictionary osmiridium — osmiridis statusas T sritis chemija apibrėžtis Platinos rūdose randamas izomorfinis Ir ir Os mišinys. atitikmenys: angl. osmiridium rus. осмирид …   Chemijos terminų aiškinamasis žodynas osmiridium — /oz meuh rid ee euhm/, n. Chem. iridosmine. [1875 80; < G; see OSMIUM, IRIDIUM] * * * …   Universalium osmiridium — os·mi·rid·i·um …   English syllables osmiridium — os•mi•rid•i•um [[t]ˌɒz məˈrɪd i əm[/t]] n. chem. mel iridosmine • Etymology: 1875–80; < G …   From formal English to slang 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”