Omphacite Thin Section

Omphacite is a member of the pyroxene group of silicate minerals with formula.

Omphacite thin section. Fe al si2o6 c 20 1m i nera ld t pub sh g v o. Beta 106 85 v 423 46 den calc 3 32. Anhedral granular to massive.

Inclusions of omphacite in garnet were observed in several thin sections and we restrict our estimates for the peak p t conditions to this and associated assemblages. Omphacite ca na mg fe 2 al si 2 o 6 it was first described in 1815 in the münchberg metamorphic complex franconia bavaria germany. A 9 585 b 8 776 c 5 26 z 4.

High relief in thin section. Both must be present and neither component more than 75 vol. Ca na mg fe 2 al si 2 o 6 it is a variably deep to pale green or nearly colorless variety of pyroxene omphacite compositions are intermediate between calcium rich augite and sodium rich jadeite it crystallizes in the monoclinic system with prismatic typically twinned forms though usually anhedral.

The name omphacite derives from the greek omphax or unripe grape for the typical green color. Garnet often pyrope or mg rich almandine and omphacite na ca al mg clinopyroxene. Large number of pages viewed.

Eclogite never contains plagioclase. Single and polysynthetic twinning on f100g common. Omphacite violan in thin section fkm 329 optic axis.

It is less commonly found in alpine metamorphic belts in blue schist metagraywacke and can also be found in. The only exception is the sample kv 06 15 figure 19 20a where matrix omphacite is in contact with garnet. Rarely in rough crystals to 5 cm.