Title
Trachyte
Identifier
HA-18
Description
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, light gray trachyte. On cut face, inclusions ranging from 0.8cm to 2cm in length with abundant vesicles less than 0.05cm in diameter can be observed.
Thin Section: Composed nearly entirely of glass material with some subhedral to euhedral plagioclase crystals that vary in size.
Date
Sample collected January, 1969
Contributor
Western Minerals
Spatial Coverage
North side of Hualalai - Puu Anahulu - Island of Hawaii
Number of Thin Sections
1