Brown crystal aggregates of the rare mineral lucasite-(Ce) from the type locality in Western Australia (Argyle Diamond Mine, Lake Argyle, Wyndham-East Kimberley Shire, Western Australia, Australia). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Lucasite-(Ce)
Lucasite-(Ce) is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula CeTi₂O₅(OH).
It crystallizes in the monoclinic crystal system (space group I2/a).
Key properties: Mohs hardness 6; specific gravity 5; White streak; Resinous luster.
IMA symbol Lca-Ce, IMA status: approved, named in 1986.
Found in heavy-media concentrates from non-sandy tuff in an olivine lamproite diatreme.
It is found associated with Calcite, dolomite, talc, titanite, manganoan ilmenite, amphibole.
The name refers to Hans Lucas, Australian geologist, CRA Exploration Pty. Ltd., who noted the mineral in concentrates.