Grayite has often been found in pegmatitic environments amongst other thorium minerals, particularly monazite ((Ce,La)PO4).

[5][6] Grayite has also been found in sedimentary environments with an observation of high concentrations in cracks raising the possibility of the mineral as a precipitate from fluid mobilized ions.

[9] These hydrated phosphate minerals often include radioactive elements such as thorium, uranium, and cerium.

[8] In the identification of new hydrated phosphate minerals related to rhabdophane XRD peak information is usually recorded through different sample preparation methods.

The peak information is analyzed again and upon doing this hydrated thorium phosphate minerals will show a monazite-like structure indicating a possible alteration relationship.