Light yellow to grey vitreous greasy crystals of the extremely rare Ca-Ba arsenate mineral morelandite the from type and only known locality worldwide in Jakobsberg mine (Jakobsberg Mine, Nordmark, Filipstad, Värmland County, Sweden). Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Morelandite
Morelandite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Ca₂Ba₃(AsO₄)₃Cl.
It crystallizes in the hexagonal crystal system (space group P6_3/m). It is a member of the Apatite structural group.
Key properties: Mohs hardness 4.5; specific gravity 5.33; White streak; Greasy to vitreous luster; optically uniaxial.
IMA symbol Mldt, IMA status: approved, named in 1977.
On a museum specimen from a metamorphosed manganese deposit.
It is found associated with Hausmannite, calcite.
The mineral was named to honor Grover C. Moreland (1912–1978), Supervisor of sample preparation, Smithsonian Institution, Washington, D.C., USA.