Browse Items (31 total)

Hand Sample: Aphanitic, light-gray alkalic olivine basalt. Sample contains abundant phenocrysts of feldspar, olivine, and augite. Phenocrysts range in diameter from 0.1cm to 0.5cm. Many of the phenocrysts in sample have an iridescent luster. Sample…

Hand Sample: Aphanitic, light gray alkalic olivine basalt. Sample contains abundant feldspar phenocrysts ranging in diameter from 0.1cm to 0.9cm in length. Phenocrysts are generally blocky in shape. Occasional vesicles throughout sample ranging in…

Hand Sample: Aphanitic light gray vesicular basalt with large olivine crystals. Olivine phenocrysts range in size from single crystals approx. 0.1cm in diameter to clusters of olivine as large as 1cm in diameter. Vesicles throughout the sample are…

Hand Sample: Aphanitic dark gray vesicular basalt. Sample contains numerous vesicles ranging in size from less than 0.05cm to 1.5cm. Individual olivine crystals can also be found throughout the sample.

Hand Sample: Aphanitic dark gray vesicular basalt. Vesicles are common throughout sample and range in size from 0.1 to 3.5cm in diameter. Individual olivine crystals are found throughout the sample and range in size from 0.1 to 0.4cm in length.

Ankaramites are dark porphyritic basalts that contain abundant pyroxene and olivine phenocrysts. Lesser amounts of biotite, and plagioclase may also be present.

Hand Sample: On cut face, aphanitic, gray basalt with light colored phaneritic crystals (~0.1 cm in size). Subparallel fractures noted across sample. Exterior of sample has been heavily weathered, resulting in the red and orange discoloration.

Hand Sample: Apahanitic, vesicular, dark gray-black basalt. Olivine crystals are scattered throughout the sample and are approx. 0.05cm in diameter. Vesicles are very predominant throughout the sample and range in diameter from 0.01 cm to 1.5 cm This…

Hand Sample: Aphanitic light gray hawaiite with inclusions containing numerous vesicles. Inclusions are darker in color with abundant vesicles less than 0.01cm in diameter. The surface of the sample is heavily weathered, resulting in sample's tan…

Hand Sample: Aphanitic light gray hawaiite. Sample contains sparse vesicles that are generally 0.1cm or less in diameter.

Hand Sample: Dark gray, vesicular, glassy sample. Sample surface has a ropey texture with vesicles ranging from 0.01cm to 2.5cm in diameter. Sample has an iridescent luster on unweathered surfaces.

Hand Sample: Lapilli tuff containing pieces of pumice (HA-23) and trachyte obsidian (HA-22) ranging in size from 0.1cm to 1.5cm. Clasts are held together in light-colored ash. Sample surface crumbles when handled. Lapilli describes the size of the…

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.

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.…

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