tartan-twinned
low-birefringence
low-birefringence
Description
Transparent colorless. Nonpleochroic. Low order birefringence colors. Distinctive twinning pattern from the intersection of pericline and albitic twins ("tartan plaid" or "cross-hatched") in cross-polarized light is virtually diagnostic of microcline. Tabular and cleavage fragments. Moderate relief.
See also feldspar.
Transparent colorless. Nonpleochroic. Low order birefringence colors. Distinctive twinning pattern from the intersection of pericline and albitic twins ("tartan plaid" or "cross-hatched") in cross-polarized light is virtually diagnostic of microcline. Tabular and cleavage fragments. Moderate relief.
See also feldspar.
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