Garronite is a series with end members:
These minerals are tectosilicates (framework silicates), zeolite group.
Garronite-Na was approved as a new mineral in 2015. Previously "garronite" had been the species name of the mineral now renamed "garronite-Ca".
Specific gravity: 2.13 to 2.18
Hardness: 4½ to 5
Colour: Colourless, white
Common impurities: Ca: Fe,Ba,K
Garronite is most common in vesicles in basalt and other
mafic rocks, often overgrown by or associated with
phillipsite, and also as epitaxial overgrowths on
The Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Quebec, Canada, is the type locality for garronite-(Na), which occurs in some metamorphic rocks and in sodalite xenoliths (Dana).
In Iceland garronite occurs at numerous localities in lavas rich in phenocrysts of anorthite variety bytownite and in non-porphyritic olivine basalt flows (HOM).
In Russia, near Nevon, on the Angara River, 50km below the Ilim River, Siberia, garronite occurs in dolerite porphyry (HOM).
The Glenariff Valley, Garron Plateau, County Antrim, Ulster, Northern Ireland, UK, is the type locality for garronite-(Ca). The mineral occurs as amygdule ̄fillings in silica-undersaturated olivine basalt flows (HOM).
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