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Chondrules in the chondrite classification Grassland. A millimeter scale is shown. Chondrules in the Carbonaceous Chondrite NWA 13887. A chondrule (from Ancient Greek χόνδρος chondros, grain) is a round grain found in a chondrite. Chondrules form as molten or partially molten droplets in space before being accreted to their parent asteroids.
Dating using 206 Pb/ 204 Pb gives an estimated age of 4,566.6 ± 1.0 Ma, [6] matching ages for other chronometers. Another indication of their age is the fact that the abundance of non-volatile elements in chondrites is similar to that found in the atmosphere of the Sun and other stars in our galaxy. [7]
These are compounds that emerged early from the primeval solar nebula, condensed out and represent the oldest minerals formed in the Solar System. [ 3 ] [ 4 ] Some primitive carbonaceous chondrites, such as the CM chondrite Murchison , contain presolar minerals, including moissanite (natural silicon carbide ) and tiny nanometer-sized diamonds ...
The abbreviation CI is derived from the C for carbonaceous and in the name scheme of Wasson, [3] the I from Ivuna, the type locality in Tanzania. The 1 in C1 stands for the type 1 meteorites in the older classification scheme of Van Schmus-Wood, [4] still used for petrography. Petrographic type-1 meteorites, by definition, have no fully-visible ...
[3] In 2006 a classification was published that assigned 7 groups to the primitive achondrites, but the classification remains controversial. The authors define primitive achondrites as meteorites "that exceeded their solidus temperature on the parent body" and thus would partially melt. Meteorites that have been fully melted are included if ...
[1] [4] Entries in the catalogue are designated with a "C" and the catalogue number (1 to 109). Unlike objects in the Messier catalogue, which are listed roughly in the order of discovery by Messier and his colleagues, [ 5 ] the Caldwell catalogue is ordered by declination , with C1 being the most northerly and C109 being the most southerly ...
[6] [7] Rose was the first to make different categories for meteorites with chondrules (chondrites) and without (nonchondrites). Story-Maskelyne differentiated between siderites, siderolites and aerolites (now called iron meteorites, stony-iron meteorites and stony meteorite, respectively). [1]
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