Cerasite

Field of view: 30 mm. Cerasite in hornfels. The hexagonal white prisms are cerasite. Cerasite is cordierite and indialite crystals replaced by muscovite or paragonite. There is a hexagonal prism of indialite at the center of the cerasite, and cordierite grew over the indialite core. Indialite is a hexagonal dimorph of cordierite and is stable at higher temperature than cordierite. Tiny hexagon at the center of cerasite is indialite, and the surrounding parts are cordierite. The black host is holnfels.

Recovered from hornfels formed by hornblende-hornfels facies contact metamorphism of S-type (Ilmenite-series) granodiorite. Formed in the Late Cretaceous (90 Ma).

Cerasite from this location was described in 1933.