CI Group

Chondrites of the CI group are named for their type specimen Ivuna, which fell in Tanzania in 1938, and there are only a handful of those rare meteorites known. The CI chondrites represent some of the most primitive meteorite . They are some of the most interesting ones.

They all belong to the petrologic type 1, which means that they suffered a large degree of aqueous alteration. Hence they don't contain any relict chondrules but instead, a large amount of water, up to 20%, in addition to lots of minerals that have been altered in the presence of water such as hydrous phyllosilicates similar to terrestrial clays, oxidized iron in the form of magnetite, and sparsely distributed crystals of olivine scattered throughout the black matrix. In addition, they contain certain amounts of organic matter like PAHs and amino acids, which are the building blocks of life on earth. Because of that peculiar mixture of water and complex organic compounds the chondrites of the CI group are suspected to contain fascinating clues to the origin of life on our planet and maybe elsewhere in the universe too!

Some researchers suggest the origin of the CI chondrites is from comets that are known to be "dirty snowballs" - a mixture of frozen water and pristine matter. Even if that isn't true, the origin of the CI chondrites is certainly in the outer reaches of our solar system since they never have been heated above 50°C during their formation and their subsequent history. Otherwise, the water would have evaporated quite rapidly and the hydrous phyllosilicates would have been metamorphosed into other minerals due to the loss of water.

ORGUEIL CI1 Fell May 14, 1864 at 8.00 PM This extremely rare carbonaceous chondrite fell in Tarn-et-Garonne, France in 1864 few minutes after 8 PM. A luminous meteor and sonic booms were followed by the fall of twenty stones; the largest stone was the size of a man's head, but most were only fist-sized. The fall covered an area of over two miles. This is the most chemically primitive of the meteorite classes. Orgueil is a micro-regolith breccia consisting of fragments up to several 100 microns in size. The matrix is composed of a heterogeneous mixture of minerals produced through aqueous alteration. Chondrules are not present, but presolar grains of graphite, diamond and corundum occur. The total recovered weight of this low-density meteorite was ~13 kg.
				15 X 10 X 7 mm !!! 1.18 gr..... solid fusion crusted (a whole face) fragment, one of the best specimen available in private hands.... Price:  SOLD
10 X 6 X 4 mm 0.24 gr solid fusion crusted fragment with huge bubbling in the crust SOLD   Price:
				12 X 6 X 5 mm 0.20 gr solid fusion crusted fragment with superb crust... Price:  SOLD
10 X 6 X 4 mm 0.28 gr  internal fragment with nice white clasts SOLD Price:
				11 X 10 X 6 mm 0.67 gr big internal fragment with nice white clasts, a good chunck Price:  SOLD
0.29 gr several fragments and dust SOLD Price: