Medium Coarse Grained Adamellite

Title

Medium Coarse Grained Adamellite

Alternative Title

Quartz Monzonite

Identifier

SFM-6

Description

Hand Sample: Holocrystalline, phaneritic, fine-to-medium-grained quartz monzonite. Mineralogy includes large plagioclase laths up to 8mm in length, quartz, alkali feldspar, biotite. Very large crystals of a dark material up to 3cm in length. Weathering to dark yellowish black and brown. Very thin vein of dark material with thermal alteration on either side.
Thin Section, XPL: Euhedral medium-grained plagioclase crystals and subhedral medium-grained quartz crystals with smaller percentages of subhedral medium-grained diopside and fine-grained biotite crystals. quartz 60%, alkali 10%, biotite 30%

Date

1/20/1969

Contributor

Western Minerals, Inc.

Spatial Coverage

St. Francois Mtns. Batholith, Missouri

Accrual Method

Purchased from Western Minerals, Inc.

Number of Thin Sections

1

Geolocation