There are different hydrates including the decahydrate, hexahydrate and tetrahydrate.

[3] An excess of oxalate is added to a hot solution of Eu3+ cations.

The resulting precipitate of Eu2(C2O4)3 ⋅ 10H2O is dried in a desiccator.

[5] The dehydration of Eu2(C2O4)3 · 10H2O occurs below 200 °C:[1] The decomposition of this compound takes place in two stages, the first at 350 °C and the second at about 620 °C.

[1][6] In the Mössbauer spectrum, Eu2(C2O4)3 · 10H2O shows an isomer shift of +0,26 mm/s with a line width of 2,38 mm/s, in reference to EuF3.