Analyses have shown that Tagish Lake fragments are of a primitive type, containing unchanged stellar dust granules that may have been part of the cloud of material that created our solar system and Sun. This meteorite shows some similarities to the two most primitive carbonaceous chondrite types, the CI and CM chondrites; it is nevertheless quite distinct from either of them. Tagish Lake has a much lower density than any other type of chondrite and is actually composed of two somewhat different rock types. The major difference between the two lithologies is in the abundance of carbonate minerals; one is poor in carbonates and the other is rich in them.