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, friable, and "ugly" meteorites - and yet 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.

Ivuna December 16, 1938 in Tanzania TKW 705 gr CI1 Type specimen Witnessed fall !
				Ivuna -00 very large chunky specimen 2.75 gr !!!!!!! SOLD
Ivuna -01 big interior fragment SOLD
				Ivuna -03 fragment 0.128gr SOLD
Ivuna -04 many fragments from this rare Ci1 0.220gr SOLD