SG Heritage Dictionary

Allanite [Noun] Webster's Dictionary 1828

1. A mineral named from Mr. Allan, of Edinburg, who first recognized it as a distinct species. It is massive, of a brownish black color, and conchoidal fracture. A siliceous oxyd of cerium.

2. A thin membrane, situated between the chorion and amnios in quadrupeds, and forming one of the membranes which invest the fetus in those animals.

Allanite [Noun] Webster's Dictionary 1913

A silicate containing a large amount of cerium. It is usually black in color, opaque, and is related to epidote in form and composition.