Davidsmithite
A calcium-bearing member of the nepheline feldspathoid group, found in a Norwegian eclogite pod.
Intro adapted from Wikipedia (CC BY-SA).
Davidsmithite is an IMA-recognized mineral species in the silicate class, with the chemical formula (Ca, )₂Na₆Al₈Si₈O₃₂.
It crystallizes in the hexagonal crystal system (space group P6_3). It is a member of the Tridymite-Nepheline, Tridymite-Nepheline structural group.
Key properties: Mohs hardness 5.5; specific gravity 2.597; White streak; Vitreous to greasy luster; optically uniaxial.
IMA symbol Dsm, IMA status: approved, named in 2016.
A rock-forming mineral in eclogite, now retrograde-altered to amphibolite facies.
It is found associated with Lisetite, albitic plagioclase, taramite.
The mineral was named to honor the contributions to mineralogy and petrology by David Christopher Smith (b. 1946), Emeritus Professor, Natural History Museum, Paris, France.