ES2 Metamorphic Rocks - Metamorphic Microstructures #2
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Granoblastic-polygonal texture.
In this cordierite-rich granulite-facies rock, textural equilibrium is
closely approached, and in section the rock consists of straight-sided polygonal cordierite grains with
120° triple junctions. Notice the very narrow biotite flake at lower right, whose basal plane the
cordierite boundaries meet at right angles.
Crossed polars. Field of view is 3.5 mm across.
Sapphirine-cordierite gneiss, Namaqualand, South Africa, Sample DWN-133
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