The mineral occurs mainly in metamorphosed clay-rich sediments and felsic igneous rocks.

[5] However, a large amount of additional elements, including Th, U, Be, Zr, P, Ba, Cr and others may be present in the mineral.

The inclusion of thorium and other radioactive elements in allanite results in some interesting phenomena.

Allanite often has a pleochroic halo of radiation damage in the minerals immediately adjacent.

[2] The type locality is Aluk Island, Greenland,[3] where it was first discovered by Karl Ludwig Giesecke.