large 223 gm. muonionalusta meteorite SLICE etched sweden std slab .5# For Sale

listing is for 1 gorgeous 223 gm.etched muonionalusta meteorite slice with stand from Sweden. .5 LBS terrific etch pattern; great for making rings. 3.75x2 INCHES.7-8 mm thick;.CompositionNew analysis of this strongly shock-metamorphosed iron meteorite has shown a content of 8.4%nickeland trace amounts of rare elements—0.33 ppmgallium, 0.133 ppmgermaniumand 1.6 ppmiridium. It also contains the inclusions oftroilite.[3]For the first time, analysis has proved the presence of a form ofquartzaltered by extremely high pressure—stishovite,[3]probably a pseudomorphosis aftertridymite. From the article "First discovery of stishovite in an iron meteorite":[2]

Stishovite, a high pressure polymorph of SiO2, is an exceptionally rare mineral...and has only been found in association with a few meteorite impact structures.... Clearly, the meteoritic stishovite cannot have formed by isostatic pressure prevailing in the core of the parent asteroid.... One can safely assume then that stishovite formation(in the Muonionalusta meteorite)is connected with an impact event. The glass component might have formed directly as a shock melt....