decipium
/dɪˈsɪpɪəm/Chemistry. Now historical and rare
noun
A (supposed) rare earth element obtained from samarskite earths.
- Decipium was soon recognized to be a mixture of samarium and one or more other rare earth elements..
Origin
Late 19th century; earliest use found in Chemical News. From French décipium from classical Latin dēcipere + French -ium.