Plate crystals dominate. They generated most of the intensity of the parhelic circle, they produced the 22° and 120° parhelia and the circumzenithal arc overhead.
Randomly oriented hexagonal prisms of some kind made the 22 degree halo and the 46° halo fragment (it could instead be a supralateral arc). Horizontal columns were in the minority giving a weak and indistinct upper tangent arc.
120° parhelion
Plate crystals with their large hexagonal faces nearly horizontal yielded the amazingly bright 120° parhelia on the parhelic circle.
In one possible ray path sunlight enters a top face, internally reflects twice and leaves through the lower face. The entrance and exit angles are equal and there is no net dispersion into colours - the 120° parhelion, unlike the 22° parhelion, is white.
Bright 120° parhelia need thick plates or ones of triangular aspect 9alternate long and short side faces).
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