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Download hereGENERAL DESCRIPTION
Analcime is an hydrated sodium aluminosilicate that belongs to the zeolites group. It is formed in particular in vacuoles of volcanic rocks, such as basalts or phonolites but also in alkaline igneous rocks.
The crystals are white, opaque and are presented in pseudo-cubic shape to a more or less complex shape, generally trapezoedric with multiples faces. It can be easily confused with leucite.
There are several layers throughout the world. In Canada: the Crowns Nest Pass in Alberta; Mont Saint-Hilaire in Québec; there are many localities in British Columbia (Ice River complex for example) and in Novia Scotia. One can also quote the Féroes islands in Denmark, Siberia, the Cyclops islands in Italy, the Cornwall area in England.
In France, analcime is present at the Puy de Marmant and Puy de Pitch in Auvergne or at the Pierre Planté Pass in Gard.
The 29 samples forming the type of this species are preserved at the Muséum national d’Histoire naturelle in Paris, in the Haüy collection (H4154 and H4154ff). They come from Aci Castello, island of Cyclades, at 8 kms from Catane in Sicily (Italy).
HISTORY : Name inspired from the Greek word [analkis] meaning weak, in reference to its weak electrical charge observed after rubing it
Species first described in 1797 by René-Just Haüy (1743-1822), French mineralogist and cristallographer
Type-locality: Iles Cyclope, Sicile, Italie
CHEMICAL FORMULA : Na Al Si2O6 H2O
CRYSTAL SYSTEM : Triclinic
COLOR : Colorless, white, greenish, gray
DIAPHANIETY : Transparent to translucent
LUSTER : Vitreous
STREAK : White
MORPHOLOGIE : Trapezohedric crystals, more often granular, compact, massive
HARDNESS : 5,0- 5,5
CHEMICAL CLASS: 2,271
DENSITY : VIII - Silicates
GROUP : Analcime
STRUNZ CLASS BEFORE 2001 : 8/J.27-10
STRUNZ CLASS AFTER 2001 : 9.GB.05
