Phillipsite

phillipsite

thomsonite

natrolite

chabazite

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The phillipsite minerals are tectosilicates (framework silicates) of the zeolite group, comprising:
Phillipsite-Ca: Ca3(Si10Al6)O32.12H2O
Phillipsite-K: K6(Si10Al6)O32.12H2O
Phillipsite-Na: Na6(Si10Al6)O32.12H2O
Phillipsite forms a series with harmotome
Members of the phillipsite subgroup.

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 is a common zeolite in basaltic cavities, ore veins, lithified rhyolitic vitric tuff, saline lake deposits and ocean floor sediments. It forms in Iceland in geothermal wells at 60 to 85oC
Phillipsite is a mineral of the zeolite facies

Localities

At the Marron Volcanics of the Olalla Area South-Central British Columbia, Canada, phillipsite was found on boulders in the talus of the White Lake Road occurrence as lustrous, orange to dark red crystals to 4 mm lining cavities. This layer is commonly overgrown by analcime and rarely by thomsonite, natrolite and a second generation of analcime. In other cavities in the same area, phillipsite occurred rarely as thin white prisms to 2 mm on colourless analcime, which was covered by yellowish calcite, then thomsonite, natrolite, and finally bladed calcite-dolomite. One find of phillipsite as blocky dark maroon crystals to 3 mm on analcime and covered in calcite was made in a cavity in the Upper Yellow Lake area. (R&M 96.6.524).

In the basaltic rocks near Kladno, Czechoslovakia, phillipsite is associated with thomsonite, mesolite, chabazite and natrolite, and it is always the first of these minerals to have been formed (DHZ 4 p398).

Phillipsite forms in Iceland in geothermal wells at 60 to 85oC.

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