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Formula: Na6(Si10Al6)O32.12H2O
Tectosilicate (framework silicate), phillipsite subgroup,
zeolite group,
zeolite facies mineral, forms series with
phillipsite-Ca and
phillipsite-K
Specific gravity: 2.2
Hardness: 4 to 5
Streak: White
Colour: White
Solubility: Moderately soluble in hydrochloric acid
Environments:
Sedimentary environments
Hydrothermal environments
Basaltic cavities (most commonly)
Phillipsite-Na is a common zeolite in
basaltic
cavities, ore veins, lithified rhyolitic vitric
tuff, saline lake deposits and ocean floor sediments.
Localities
At the Kulnura quarry, Central Coast, New South Wales, Australia, colourless and pale yellow to dark orange crystals of
phillipsite to 0.7 mm occur within fractures in sedimentary xenoliths and throughout
basanite at the Kulnura volcano.
The lighter coloured crystals are phillipsite-(K) and the darker ones are phillipsite-Na. The colour may be
due to minor iron within the phillipsite crystal, or to hematite/
goethite coating micro fractures and occuring in spaces between crystals. Vesicles
within the basanite are filled with
chabazite, calcite and phillipsite,
and secondary mineralisation along joints is commonly
analcime, natrolite,
calcite and phillipsite
(AJM 21.1.7-17)
The type locality is Rupe di Aci Castello, Aci Castello, Metropolitan City of Catania, Sicily, Italy.
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