Browse Items (47 total)

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: 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…

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: 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 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 dark gray trachyte. Sample contains zones with abundant tiny vesicles (less than 0.1cm in diameter), however the majority of the sample does not contain any vesicles or phenocrysts.

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

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

Trachytes are an igneous volcanic rock with an aphanitic or porphyritic texture. Alkali feldspar, low amounts of plagioclase and quartz or a feldspathoid are common in trachytes.

Hand Sample: Aphanitic dark gray vesicular basalt. The vesicles are uniform and common throughout the sample, with diameters of approx. 0.05 cm.

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: 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 medium gray vesicular basalt with scattered olivine crystals. Olivine crystals are commonly growing either in clusters or as one single crystal. Vesicles are found throughout sample and range in diameter from 0.05cm to 2cm.

Hand Sample: Aphanitic dark gray vesicular basalt. Basalt has ropey pahoehoe texture on top surface and contains numerous elongated vesicles.

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.

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 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 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 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…