vitric การใช้

• Founded in 1824 by Alexandre Brongniart, director of the Manufacture nationale de S鑦res, under the name of Ceramic and Vitric Museum.
• These deposits consists of volcanic ash, pumice and rhyolite, forming layers with angular pumice and ash and an abovelying layer of vitric rhyolite, similar to the rampart wall.
• Vitric ash particles from high-viscosity magma eruptions are typically angular, vesicular pumiceous fragments or thin vesicle-wall fragments while lithic fragments in volcanic ash are typically equant, or angular to subrounded.