Browse Items (41 total)

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

Quartz and feldspar appear to be shattered

Mined and marketed under the name "Aplite"

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

Sample comes from flow rocks that are associated with lithic fragment tuffs, pyroxene and chlorite are present as an interstitial material

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

Shows considerable fracturing, thin section examination shows ophitic texture

Ophitic texture in thin section, plagioclase exhibits some alteration to sericite

Ophitic texture in thin section, some opaques

Quarred for monumental stone, ophitic texture in thin section, minor amount of opaques

Mostly plagioclase and biotite

Much of the plagioclase has been altered to epidote and sericite, hornblende occurs as long prismatic crystals arranged in sprays

Contains secondary products of alteration including serpentine, talc, chlorite, carbonates, and iron oxides

Contains inclusions of relict gabbro

Fedlspar is cream-pink colored and much has been altered to sericite/epidote

Rock may have undergone some alteration

Amphibole, epidote, chlorite, quartz, calcite, and clinozosite present are thought to be alteration products

Rock appears to be hydrothermally altered, sample is taken from a sill and is source of basaltic tuffs in area

Rock has been subjected to alteration and shear forces, the garnet present is probably an alteration product

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