Browse Items (1651 total)

foliated

Hand Sample: Holocrystalline, phaneritic, medium-grained granitoid with an abundance of alkali feldspar. Other minerals include quartz and biotite. Some chemical weathering has produced a white coating.

Hand Sample: Holocrystalline, phaneritic, medium-grained granite composed predominantly of smaller alkali feldspar crystals with larger crystals of smoky quartz, biotite, and plagioclase feldspar

Granite containing hornblende and, locally, hastingsite, ferrohedenbergite, or fayalite.

Granite containing hornblende and, locally, hastingsite, ferrohedenbergite, or fayalite

Green granite; contains hornblende and, locally, hastingsite, ferrohedenbergite, or fayalite

Massive red granite. Grain size ranges from coarse to fine.

fine-coarse grained pink granite

The granites at this locality are intruded by aplite dikes (WMB-6)

fine grained

coarse grained, porphyritic

Hand Sample: Holocystalline, phaneritic, medim-grained granitoid with subhedral grains of smoky quartz, plagioclase feldspar, potassium feldspar, and biotite. Weathering to red-yellow on some surfaces.

Granite from the Concord Granite series. Thin section contains plagioclase, alkali feldspar, biotite, quartz, and muscovite. Hand sample shows feldspars, quartz, and micas.

1:62500

1:62500

OCR PDF of supplemental information for the Grand Canyon collection.

Fenitized Gneiss. Gneiss discovered in direct contact with pyroxenite in prospect trench on ridge, about 500 ft. west of PH-1.. .

coarse-grained

cordierite-bearing