Meionite

Vesuvianite and Meionite San Vito quarry, Ercolano, Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania, Italy Specimen weight:274 gr. Crystal size:to 0.8 cm Overall size: 100mm x 64 mm x 50 mm © minservice

Chemical Formula: Ca4Al6Si6O24CO3
Locality: Mte. Somma, Vesuvius, Italy.
Name Origin: From the Greek for “less”, referring to its less acute pyramidal form compared with vesuvianite.
Meionite is a tectosilicate belonging to the scapolite group with the formula Ca4Al6Si6O24CO3. Some samples may also contain a sulfate group. It was first discovered in 1801 on Mt Somma, Vesuvius, Italy.

History

Discovery date : 1801
Town of Origin : MONTE SOMMA, MT. VESUVE (VOLCAN), NAPLES, CAMPANIE
Country of Origin: ITALIE

Optical properties

Optical and misc. Properties: Transparent to subtranslucent
Refractive Index : from 1,55 to 1,60

Physical Properties

Cleavage: {???} Distinct, {???} Indistinct
Color:     Bluish, Brownish, Colorless, Violet, Greenish.
Density: 2.66 – 2.73, Average = 2.69
Diaphaneity: Transparent to subtranslucent
Fracture: Sub Conchoidal – Fractures developed in brittle materials characterized by semi-curving surfaces.
Hardness: 5-6 – Between Apatite and Orthoclase
Luminescence: Fluorescent, Short UV=yellow-white, Long UV=red.
Luster: Vitreous – Resinous
Streak: colorless

Photos :

Meionite Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania, Italy Specimen weight:52 gr. Crystal size:0,6 cm Overall size:5,5 x 3,5 x 3 cm © minservice
Meionite var. Mizzonite Pianura, Campagna, Italy (TYPE LOCALITY) Small Cabinet, 6.6 x 5.8 x 2.0 cm © irocks
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