Alkalic Olivine Basalt
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 has very few vesicles, which are generally less than 0.1cm in diameter.
Thin Section: Groundmass of plagioclase grains. Phenocrysts of plagioclase, olivine and augite are abundant throughout sample.
Sample collected January, 1969
Western Minerals
HA-9
Alkalic Olivine Basalt
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 diameter from 0.05cm to 0.3cm.
Thin Section: Groundmass of plagioclase grains. Large plagioclase and feldspar phenocrysts are abundant throughout sample. Some vesicles present in thin section.
Sample collected January, 1969
Western Minerals
HA-10
Alkalic Olivine Basalt
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 primarily large and also elongate in shape.
Thin Section: Groundmass composed of small sized plagioclase grains, glass, and clinopyroxene. Some small phenocrysts of olivine present throughout the thin section.
Sample collected in January, 1969.
Western Minerals
HA-21
Alkalic Olivine Basalt
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.
Thin Section: Groundmass of medium size plagioclase, pyroxenes, and olivine. Vesicles are numerous throughout the sample.
Sample collected in January, 1969.
Western Minerals
HA-27
Alkalic Olivine Basalt
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.
Thin Section: Groundmass dominated by plagioclase, glass and pyroxenes. Large phenocrysts of euhedral to subhedral olivine can be observed throughout the sample in addition to occasional vesicles.
Sample collected in January, 1969.
Western Minerals
HA-28
Ankaramite
Ankaramites are dark porphyritic basalts that contain abundant pyroxene and olivine phenocrysts. Lesser amounts of biotite, and plagioclase may also be present.
Hand Sample: Aphanitic dark gray vesicular Ankaramite. Sample contains abundant vesicles ranging in size from less than 0.05cm to 0.8cm. Sample also contains numerous larger crystals with iridescent luster ranging in size from 0.1cm to 0.8cm. Phenocrysts of olivine approximately 0.2cm in diameter can also be found throughout the sample.
Thin Section: Groundmass made up of microcrystals of clinopyroxenes, glass, plagioclase. Phenocrysts of olivine and pyroxenes are present in addition to some accessory biotite grains.
Sample collected in January, 1969.
Western Minerals
HA-19
Basaltic Spatter
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.
Thin Section: Groundmass of aphanitic plagioclase. Some larger plagioclase grains are found throughout the sample in addition to some olivine phenocrysts. Vesicles are present throughout sample.
Sample collected January, 1969
Western Minerals
HA-4
Clinkery aa
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 sample displays characteristics of rough aa texture. The surface of the rock is dark red-brown likely due to weathering.
Thin Section: Aphanitic groundmass composed of mainly glass and microcrystals of clinopyroxene. Medium size, elongated, euhederal plagioclase crystals are present that display twinning.
Sample collected January, 1969
Western Minerals
HA-15
Hawaiite
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 color.
Thin Section: Aphanitic groundmass of plagioclase, interstitial glass, and microcrystals of clinopyroxenes.
Sample collected January, 1969
Western Minerals
HA-11
Hawaiite
Hand Sample: Aphanitic light gray hawaiite. Sample contains sparse vesicles that are generally 0.1cm or less in diameter.
Thin Section: Composed primarily of medium size plagioclase crystals with some microcrystals of pyroxene.
Sample collected in January, 1969.
Western Minerals
HA-20
Iridescent Pahoehoe
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.
Thin Section: Aphanitic opaque groundmass with phenocrysts of amphiboles, plagioclase, and olivine. Vesicles are abundant throughout thin section.
Sample collected January, 1969
Western Minerals
HA-6
Lapilli Tuff
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 clasts, indicating a range in diameter of approx. 2 to 64mm.
Thin Section: Groundmass is predominantly clasts of pumice and trachyte obsidian, which are composed of glass and plagioclase grains in a glass matrix material.
Western Minerals
HA-24
Melilite Nephelinite
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.
Thin Section: Groundmass composed of euhedral quartz grains with abundant phenocrysts of olivine and pyroxenes.
Sample collected in January, 1969.
Western Minerals
HA-30
Nephelinite
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.
Thin Section: Groundmass is primarily glass and pyroxenes. Phenocrysts of pyroxenes and olivine are present throughout the sample.
Sample collected in January, 1969.
Western Minerals
HA-29
Oceanite
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 0.8cm. Vesicles are very predominant, and range from 0.01 cm to 1 cm in diameter
Thin Section: Aphanitic groundmass of plagioclase, interstitial glass, and microcrystals of clinopyroxene. Phenocrysts of olivine, pyroxene, amphiboles, and plagioclase are present. Vesicles are roughly ~.01mm in diameter and present throughout the sample.
Sample collected January, 1969
Western Minerals
HA-8
Oceanite
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 flow.
Thin Section: Groundmass composed of mainly of glass, plagioclase, microcrystals of clinopyroxene. Thin section also contains phenocrysts of olivine and pyroxene.
Sample collected January, 1969
Western Minerals
HA-16
Peridotite/Dunite
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.
Thin Section: Large euhedral to subhedral olivine grains compose the majority of the sample, with thin bands of glass material between them.
Sample collected in January, 1969.
Western Minerals
HA-25
Pumice
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.
No Thin Sections of this sample
Sample collected January, 1969
Western Minerals
HA-5
Pumice
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. Sample contains blocks of Trachyte Obsidian from sample HA-22.
Thin Section: Groundmass composed of aphanitic glass, opaque minerals, and some plagiocalse. Numerous vesicles are present.
Sample collected in January, 1969.
Western Minerals
HA-23
Rhyodacite
Hand Sample: Aphanitic, pink-black rhyodacite. Sample contains alternating black and dark pink bands across face. Sample does not contain any vesicles or phenocrysts.
Thin Section: Groundmass is microcrystalline, with abundant phenocrysts of plagioclase, olivine, and pyroxenes.
Sample collected in January, 1969.
Western Minerals
HA-31