The mineral eudialyte (Eudialiet) is a chlorine-containing sodium-calcium-cerium-iron-manganese-yttrium-zirconium-silicate having the chemical formula Na 4 (Ca, Ce) 2 (Fe2 +, Mn, Y) ZrSi8O22 (OH, Cl) 2. The mineral belongs to the cyclo silicates. Yellow, tan, pink, red or purple eudialyte has a glass sheen, a white stripe coloring and an imperfect cleavage according to the crystal surface . The average density is 2.9 and the hardness is from 5 to 5.5. The crystal system is trigonal and the mineral is mildly radioactive. The gamma ray value according to the American Petroleum Institute is 7287.91. The name of the mineral eudialyte is derived from the Greek εὐδιάλυτος eudiálutos, easy fissile  composed of the words εὖ eu, good. and διάλυτος diálutos, fissile. The mineral eudialyte is especially common in nepheline syenieten. The type of location is the Julianehåb district in Greenland. The mineral is also found in Quebec, Canada.