A Grt | Crd | Sill | Bi gneiss from Koliakode quarry in the Trivandrum Block of the Southern Granulite Terrane, India. Most likely a Palaeoproterozoic pelitic protolith that was metamorphosed at temperatures over 900 degrees in the mid-crust for around 100 Myr during the amalgamation of Gondwana from 620-520 Ma.