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Download hereGENERAL DESCRIPTION
Mesolite is an hydrated aluminium, calcium and sodium silicate. It is formed within the cavities of volcanic rocks (basalts, andesites) and in hydrothermal veins.
The crystals are prismatic and elongated, they can be assembled within fibrous aggregates that measures sometimes more than 30 cm. Mesolite is generally colourless, white or gray.
It is a species which one finds associated with natrolite, scolecite or calcite. Among the localities: Poonah (India) and Globe (USA), many deposits in Australia, Scotland, Ireland and Canada. In France: Puy-de-Marman (Puy de Dôme) and the Mont Sémiol (Loire).
The place of conservation of the type of this species is not known.
HISTORY : Name inspired from the Greek word "μεσοσ" [mesos] meaning the "center". Name given to mark the transition between natrolite et scolecite
Species first described in 1816 by Johann Nepomuk Fuchs (1774-1856) and Adolf Ferdinand Gehlen (1775-1815 ), German chemists and mineralogists
Type-locality : Faroe Islands, Denmark
CHEMICAL FORMULA : Na2 Ca2 Al6 Si9 O30 8H2O
CRYSTAL SYSTEM : Orthorhombic
COLOR : Colorless, white, gray, yellowish
DIAPHANIETY : Transparent to translucent
LUSTER : Vitreous to silky
STREAK : White
MORPHOLOGIE : Prismatic crystals, elongated, fibreous aggregates
HARDNESS : 5
CHEMICAL CLASS: 2,27
DENSITY : VIII - Silicates
GROUP : Natrolite
STRUNZ CLASS BEFORE 2001 : 8/J.21-50
STRUNZ CLASS AFTER 2001 : 9.GA.05
