Morphological evidence for diffusion-controlled growth of garnet from metapelites

The surface microtopography of garnet from metamorphic schists of the northern Ladoga region has been investigated. The morphology of garnet is distinguished by a rough stepped surface on dodecahedral faces {110} and by the absence of sharp crystal edges. As follows from experimental results on crystal growth under hydrothermal conditions, the microtopography pattern gives evidence for a highly oversaturated inter-granular medium and the important role of diffusion as a factor controlling garnet growth.