kyanite crystals in quartz - São José de Safira, Minas Gerais, Brazil - hand/display specimen and they range from faint

and they range from faint to obvious

Radiocarbon dating of broken and undisturbed layers would bracket the age of the fault rupture

Note that these have been affected by covid

Tuffs are light colored

kyanite crystals in quartz - São José de Safira, Minas Gerais, Brazil - hand/display specimen and they range from faintkyanite Al2SiO5 Kyanite forms when aluminum rich rocks are metamorphosed, and is frequently found in schists that formed at medium to high pressures and lower temperatures in areas of regional metamorphism. At higher temperatures, kyanite converts to sillimanite. Occasionally the metamorphism produces a pegmatite with large crystals that form when a fluid rich magma allows rapid movement of atoms. These large crystals of kyanite and the surrounding