spectacle (1) substitution (1) association (1) diffusion (1) cation (1) Development (1) Context (1) Hydrothermal alteration (1) Spinel (1) Social groups (1) Serpentine (1) Ultrabasic rocks (1) Peridotite (1) Magnetite (1) Grain (1) Exchange (1) Diffusion (1) Chromite (1) diffusion (1) graduel (1)