Gmelinite-Na Locality: Flinders , Victoria , Australia ( Locality at mindat.org ) Gmelinite is one of the lesser-known and rarer zeolite minerals (hydrated sodium calcium aluminum silicate). There are well-formed crystals here of the very unique angular "flying saucer" shape the best crystals show. Good luster on the faces, too! 7.4 x 5.8 x 2.7cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Gmelinite-Na
Gmelinite is a series of rare zeolite minerals. The most common member is gmelinite-Na; others are gmelinite-Ca and gmelinite-K. It is closely related to the very similar mineral chabazite. Gmelinite was named as a single species in 1825 after Christian Gottlob Gmelin (1792–1860) professor of chemistry and mineralogist from Tübingen, Germany, and in 1997 it was raised to the status of a series.Gmelinite-Na has been synthesised from Na-bearing aluminosilicate gels.
Intro adapted from Wikipedia (CC BY-SA).
Gmelinite-Na is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₄(Si₈Al₄)O₂₄·11H₂O.
It crystallizes in the hexagonal crystal system (space group P6_3/mmc). It is a member of the Gmelinite structural group.
Key properties: Mohs hardness 4.5; specific gravity 2.02–2.17; Vitreous luster; optically uniaxial.
IMA symbol Gme-Na, IMA status: approved, named in 1825.
Formed from sodium-rich fluids, in basalts and related igneous rocks, also pegmatites.
It is found associated with Zeolites, calcite, aragonite, quartz.
The name refers to Christian Gottlob Gmelin (1792-1860), mineralogist and chemist of Tübingen, Germany. The suffix indicates the dominance of Na as the extra-framework cation.