Gmelinite-Ca Locality: Sarbaiskoe deposit (Sarbai; Sarbay Mine), Qostaney Oblysy (Kostanai [Kustany] Oblast'), Kazakhstan ( Locality at mindat.org ) Size: 7.9 x 5.9 x 5.1 cm. Rudnyi is best known for its beautiful yellow calcites, but here is a rare zeolite from the locality: a rich specimen of gmelinite, with translucent, salmon-colored crystals that are quite sizeable and eye-visible covering the entire face of the matrix. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Gmelinite-Ca
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-Ca is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₂(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 2.11; Vitreous.] luster; optically uniaxial.
IMA symbol Gme-Ca, IMA status: approved, named in 1978.
Formed from calcium-rich fluids, in basalts and related igneous rocks, also pegmatites.
It is found associated with Analcime, chabazite, calcite, aragonite, quartz.
The name refers to Christian Gottlob Gmelin (1792-1860), mineralogist and chemist of Tübingen, Germany. The suffix indicates the dominance of Ca as the extra-framework cation.