#DogWalkingGeology from a couple of days ago - Spud has found some super sillimanite at Bendoran, as pale knobbly lumps (with a little coexisting pink andalusite) , sticking out of metapelite.These are probably replacements of older, large regional-metamorphic kyanite crystals due to high temperature reheating by intrusion of the Ross of Mull Granite. #Mull #Geology #Metamorphic #Al2SiO5

#DogWalkingGeology from this morning. Here's a lovely wee layer of pale blue elongate kyanite crystals, pale pink elongate andalusite, plus some wee brown round garnets, in schist from Ardalanish Bay. Although the andalusite and kyanite look happy together, they are not actually in equilibrium: this layer has "frozen" during the slow process of converting kyanite to andalusite. Reactions are all about the kinetics! #Metastable #Mull #Moine #RossOfMullGranite #Geology #Minerals #Al2SiO5 #Kinetics