Browse Items (41 total)

  • Collection: (SE) Southeastern Igneous Suite -- Southeastern United States

Chlorite, epidote, and mica are present as secondary minerals

Quartz and feldspar appear to be shattered

Some feldspar shows slight alteration

Contains sutured grain boundaries, conversion of hornblende to magnetite, and some fine-grained alteration products

Similiar in composition, texture, and shape to the Concord, North Carolina complex

Contains augite, amphibole, plagioclase, ziron, opaques, and a fine-grained alteration product (unknown)

Contains inclusions of relict gabbro

Quartz and feldspar phenocrysts, rounded diabase inclusions

Phenocrysts of lath shaped feldspars and beta quartz

Contains orthoclase, ligoclase, and quartz phenocrysts and has alterations of kaolinite, sericite, and epidote

Biotite and feldspar are aligned, giving the rock a texture like porphyroblastic gneiss, some feldpsar has been altered to sericite, and some larger feldspar crystals are fractured

Biotite forms lineation in some hand specimens, much of the quartz and feldspar is fractured

Quartz and feldspar exhibit fracturing

Fedlspar and quartz exhibit fracturing

Extensively used in highway construction

Quatz appears strained, microcline is altered to muscovite and sericite, biotite is altered to chlorite

Quartz and feldpsar grains are closely interlocked and grains appear to be shattered

Exhibits a runic texture, the kind that is found in feldspar mining operations (undesirable due to high amount of quartz)

Biotite is variable in amount, but it is always evenly distributed