[meteorite-list] Carbonados
From: bernd.pauli at paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: 27 Feb 2007 20:30:08 UT Message-ID: <DIIE.000000BC00001790_at_paulinet.de> Elton wrote: "As far as I know the diamonds are only found in rim recoveries." Hello Elton, Marcin, and List, Nininger was the one who first observed that diamonds were only found in fragments recovered from the rim. All these meteorites had a reheated, granulated matrix. Nininger suggested that the temperatures indicated were those required to form diamonds from graphite during the passage of shock waves produced in the meteorite upon collision with the Earth. Most carbonados are about 0.1-1.0 mm (some up to 2.2 mm) in diameter, a little porous, layered and polycrystalline. They usually occur in amorphous carbon-graphite-troilite nodules. Many of the carbonados are aggregates of diamond and a hexagonal polymorph of diamond called lonsdaleite. Reference: BUCHWALD V.F. (1975) Handbook of Iron Meteorites (Volume 2, Canyon Diablo, pp. 384-385). Best wishes, Bernd Received on Tue 27 Feb 2007 03:30:08 PM PST |
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