A plural or variant form related to certain mineral or geological classifications, though this term is extremely rare in modern usage.
This appears to be a specialized mineralogical or geological term of uncertain origin, possibly from Italian or Latin roots, but its exact etymology is obscure in contemporary dictionaries.
This word is so rare that even most geologists have probably never encountered it—it might be a forgotten technical term that lost relevance when scientific nomenclature was modernized and standardized.
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