Tectosilicate (framework silicate), scapolite group. Scapolite is the marialite-meionite series
Specific gravity: 2.74 to 2.78
Hardness: 5 to 6
Colour: Colourless, white, grey, pink, violet, blue, yellow, orange-brown, brown
Common impurities: Mg,Na,K,Cl,H2O,S
Metamorphic environments typical
Meionite occurs typically in regionally metamorphosed rocks,
especially marble, calcareous gneiss,
granulite and greenschist. Also
in skarn, some pegmatites, altered mafic
igneous rocks and ejected volcanic blocks. Associated minerals include plagioclase,
titanite and zircon
At the type locality, Monte Somma, Somma-Vesuvius Complex, Naples, Campania, Italy, meionite was found in a geode from volcanic ejecta mainly composed of limestone associated with pyroxene and leucite (AM 67.1229-1241).
At Manchester, New Hampshire, USA, meionite has been found as irregular columnar masses in a biotite schist with narrow calcareous bands interbedded with granite and pegmatite lenses (AM 67.1229-1241).
Approximately 100 meters northeast of the wollastonite - diopside locality off Rose Road, Pitcairn, Saint Lawrence county, New York, USA, there is another collecting site where meionite occurs as sharp prismatic crystals to 20 cm, and massive, yellow-gray meionite that fluoresces bright yellow in longwave ultraviolet radiation occurs in pegmatitic intergrowths with diopside and calcite (R&M 90.5.446).
Back to Minerals