Origin of color variations of thin, nano-sized layers of volcanic cinder from the Sierra Negra Volcano of the Galapagos Islands

Volcanic cinder, also known as scoria, is an extrusive igneous rock that forms when gas-rich magmas of basaltic or andesitic composition cool quickly. It typically dark in color, ranging from black to red depending on its chemical composition. Sometimes fresh cinder samples show a variety shiny metallic colors surface blue gold silver. The origin these has remained unknown up now. Cinder eruptive event occurred October 2005 have been collected the surroundings Sierra Negra volcano Galápagos Islands. samples’ crystallographic structure, composition, and morphology analyzed using X-Ray diffractometry (XRD), energy dispersive spectroscopy (EDS) field gun emission scanning electron microscopy (SEM), respectively. Based extensive physical analysis, we were able demonstrate are due light interference phenomenon. These results great potential be used for wide purposes such determining temperature magma evaluating volcanic planetary studies.