Origin and significance of inclusions in quartz; a cautionary example from the Tanco Pegmatite, Manitoba

The ambiguity of morphological criteria for the primary nature of fluid inclusions is illustrated. Spodumene and quartz formed from the isochemical breakdown of petalite have trapped two very different types of liquid: spodumene the pegmatitic liquid at the stage of petalite breakdown and quartz a succession of later and cooler fluids. Fluid inclusions in quartz are argued as being perhaps generally secondary despite any appearance of a primary nature. 'Primary' is equated with the ambient fluid of crystallization of the inclusion-hosted mineral.