French Mills Rhyolite

Title

French Mills Rhyolite

Identifier

SFM-17

Description

Hand Sample: Phaneritic rhyolite with fine-grained phenocrysts of quarts, feldspar and hornblende in a brownish-red groundmass. Weathers to orange-brown.
Thin Section, XPL: 50% medium-to-fine grained subhedral well-weathered plagioclase crystals, some rimmed in opaques. 50% matrix.

Date

1/20/1969

Contributor

Western Minerals, Inc.

Spatial Coverage

St. Francois Mountains Batholith, Missouri

Accrual Method

Purchased from Western Minerals, Inc

Number of Thin Sections

2