Mica in Quartz

Micas are common in igneous, metamorphic and sedimentary rocks (The Open University), and muscovite is typical of granites and granite pegmatites (University of Minnesota). The Quartz Page notes that fine flakes of mica falling from pocket walls onto growing quartz crystals can be enclosed and form phantoms, and GIA described quartz with muscovite and clinochlore spheres on phantom planes from Larimer County, Colorado. The retailer Pascle lists Brazil, India, Madagascar and Zambia as sources.

Mica flakes are platy and split along a single perfect cleavage (The Open University); they are far softer than the quartz host (biotite 2.5 to 3 against 7 for quartz). Colour gives only a rough guide to the mica species; GIA identified muscovite inclusions by Raman analysis. Transparent quartz with scattered mica crystals should be distinguished from aventurine, which geology.com describes as translucent quartz or quartzite with abundant small platy inclusions, most often green fuchsite, that produce a glittering effect called aventurescence.

IGS lists no special care instructions for quartz itself. The retailer Pascle advises avoiding strong knocks, long exposure to salt or chemicals, and ultrasonic cleaners, because the included mica is a soft, layered mineral that splits easily.

The retailer Pascle associates mica in quartz with inspiration, insight and letting one's individuality shine, linking the sparkle of the mica with the "purifying" role it attributes to clear quartz. These are retailer beliefs, not verified properties.