[3] The compound does not dissolve in water and forms crystalline hydrates—colorless crystals.

[4] Precipitation of soluble yttrium salts with oxalic acid:[5] Yttrium oxalate is highly insoluble in water and converts to the oxide when heated.

[6] Yttrium oxalate forms crystalline hydrates (colorless crystals) with the formula Y2(C2O4)3•n H2O, where n = 4, 9, and 10.

Decomposes when heated: The solubility product of yttrium oxalate at 25 °C is 5.1 × 10−30.

[8] Several yttrium oxalate double salts are known containing additional cations.