Trachyte

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