Formula: (Na,K,Ca)2CO3
Origin of name: For J. Gregory, geologist in East Africa
Crystal system: Hexagonal
Crystal class: 6mm
Twinning:
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Diaphaneity:
Luster:
Habit: As microphenocrysts to phenocrysts to 3 mm
Hardness:
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Streak:
Synonyms/varieties:
Comments: name was approved and is in usage by petrologists, but full description has not been published
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