Depmeierite
Depmeierite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₈[Al₆Si₆O₂₄](PO₄,CO₃)₁₋ₓ·3H₂O (x< 0.5).
It crystallizes in the hexagonal crystal system (space group P6_3). It is a member of the Cancrinite structural group.
Key properties: Mohs hardness 5; specific gravity 2.32; White streak; Vitreous luster; optically uniaxial.
IMA symbol Dep, IMA status: approved, named in 2009.
Found in a peralkaline hydrothermal veinlet cross-cutting alternating foyaite, urtite, and lujavrite rocks in an alkaline igneous complex.
It is found associated with Natrolite, steenstrupine-(Ce), epistolite after vuonnemite, sodalite, and minor aegirine, serandite, natisite, and vitusite-(Ce).
The mineral was named to honor Wulf Helmut Heinz Depmeier (b. 1944), professor of mineralogy and crystallography, Christian Albrecht University, Kiel, Germany.