Browse Items (47 total)

Metamorphised Balmville limestone with visible phlogopite crystals. Also contains actinolite.

Thin section shows calcite with interspersed pleochroic phlogopite.

Metamorphised Balmville limestone with visible phlogopite crystals. Also contains tremolite visible at the outcrop level. Within nose of anticline of Walloomsac schist.

The PPL thin section shows a large irregular calcite grain with tremolite at…

Hand Sample: Aphanitic light gray nephelinite containing some melilite. Melilite is the white minerals that range in size from 0.1 to 0.5cm. Sample contains numerous small sized (less than 0.05cm) vesicles that are evident on the cut face.

Extremely coarse-grained muscovite schist. Large garnets visible in hand sample. Sillimanite is not recognizable in hand sample, however.

The thin section shows muscovite (with minor sillimanite) in a large band, biotite, staurolite, and…

Hand Sample: Aphanitic medium gray nephlenite. White intergrowth crystals are common throughout the sample and form long strands (approx. 0.6 - 1cm in length) on sides of sample. Sample contains some melilite.

Hand Sample: Aphanitic dark gray vesicular oceanite with phaneritic olivine crystals. Olivine crystals are scattered throughout the sample and are either growing in clusters or as a single crystal. Olivine crystals range in diameter from 0.1cm to…

Hand Sample: Aphanitic dark gray vesicular basalt with olivine crystals scattered throughout. The olivine crystals are most common in this sample than in other samples within the suite. Sample was collected from an olivine-rich zone within Mauna Loa…

Hand Sample: Natural surface of sample is dark in color with smooth texture. Cut face reveals blocks of peridotite and dunite held together with a thin layer of lava cement. Sample has high specific gravity.

Hand Sample: Glassy, dark gray, vesicular pumice. The sample contains many small pieces of the pumice, ranging from 0.03cm to 1.5cm in diameter. Chunks of glassy pumice and volcanic ash compose sample.

Hand Sample: Aphanitic light gray vesicular pumice. Sample has incredibly low specific gravity due to abundant vesicles. Vesicles range in size from less than 0.1cm to 0.3cm. Some vesicles on cut face appear to be filled in with a lighter material.…

Metamorphised sandstone with a gray, glassy appearance. From the Paughquag quartzite, a late Cambrian formation. The basal Cambrian quartzite rests on pre-Cambrian gneisses.

The thin section shows quartz and plag with some biotite and grain…

Red shale from the Indian River member of the Normanskill formation. This rock contains hematite, chlorite, muscovite, plagioclase, and quartz.

The thin section shows muscovite and biotite with some larger quartz grains visible and minor hematite…

Hand Sample: Aphanitic, pink-black rhyodacite. Sample contains alternating black and dark pink bands across face. Sample does not contain any vesicles or phenocrysts.

Hand Sample: Microcrystalline vesicular, dark-gray to black scoria. Vesicle size varies throughout the sample, ranging from larger circular vesicles with a diameter of approx. 1.5 cm on one surface and small vesicles (less than 0.1cm in diameter) on…

Kink fold in a slate from the Mt. Merino Member.

This rock is from the chlorite zone of the Barrovian metamorphic sequence (low metamorphism).

Schist bearing both staurolite and chloritoid. This marks the first appearance of staurolite in the metamorphic sequence. Also contains garnet, muscovite, chlorite, biotite, feldspar, and quartz. The assemblage in not in equilibrium.

The thin…

Schist with coarse staurolite grains. This outcropping is approximately on the strike of the chloritoid schists (sample 7). Also contains garnet, muscovite, feldspar, and quartz. Presumed to be from the Everett Schist.

The thin section shows…

Hand Sample: Aphanitic vesicular dark gray-black basalt. Sample contains numerous vesicles ranging in size from 0.01cm to 1.5 cm.

Hand Sample: Apahanitic vesicular dark gray-black basalt. Larger (

Hand Sample: Aphanitic vesicular dark gray-black basalt with larger light crystals throughout the sample. The vesicles throughout the sample are elongate in shape, and range in size from 0.5 cm to 2.5 cm. Sample surface displays rough AA texture.