Polymict

It is pointed out that the breccias among stony meteorites are mainly of two kinds : (a) breccias in which the enclosed fragments are of the same material as the surrounding principal mass of the stone: it is proposed to call this kind of breccias “monomict breccias,” and (b) breccias in which the enclosed fragments are of a foreign material as compared with the surrounding principal mass of the stone: it is proposed to call these breccias “polymict breccias.”

The ‘monomict’ meteorites are samples of a single lithology while the polymict meteorites are those containing two or more lithologies.