Staurolite
zone (Sample
1213)
The assemblage
is St + Grt + Bt + Ms + Pl + Qtz.
The most conspicuous mineral is staurolite (yellow
pleochroic, high relief, low birefringence),
forming porphyroblasts up to 4 mm long. It has
inclusions of quartz which commonly define curved
trails (syntectonic growth). Garnet forms equant
porphyroblasts. The remaining major minerals are
muscovite, quartz, biotite and plagioclase, with
the micas defining a contorted schistosity.
Field of view
is 6 mm wide.
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