Carbobystrite
Carbobystrite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₈(Al₆Si₆O₂₄)(CO₃)·4H₂O.
It crystallizes in the hexagonal crystal system (space group P31c). It is a member of the Cancrinite, Cancrinite-sodalite structural group.
Key properties: Mohs hardness 7; specific gravity 2.366; White streak; Vitreous luster; optically uniaxial.
IMA symbol Cbys, IMA status: approved, named in 2009.
From zoned hyperagpaitic pegmatite in an ijolite-urtite body near its contact with apatite-nepheline rocks and apparently crystallized from residual peralkaline pegmatite-forming melt or solution.
It is found associated with Sodalite, megakalsilite, natrite, bitumen.
The name refers to the compositional relationship with bystrite {(Na, K)7Ca[Al6Si6O24](S)1.5·H2O} and the essential role of CO3 in the compound. It is a K-deficient, (CO3).