igneous/metamorphic

Quartz with Mica (Schist/Pegmatite fragment)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

Hardness: 7 (Quartz) and 2-3 (Mica); Color: Translucent white to tan (quartz) with dark brown/black layers (biotite/mica); Luster: Vitreous to pearly; Crystal structure: Trigonal (quartz) and Monoclinic (mica); Cleavage: None for quartz, perfect basal for mica.

Hardness: 7 (Quartz) and 2-3 (Mica)
Luster: Vitreous to pearly

Identified April 7, 2026More igneous/metamorphic →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Likely formed in a pegmatite vein or within a high-grade metamorphic environment (schist/gneiss contact). These minerals crystallize from silica-rich fluids underground or during intense pressure/heat of mountain-building events.

Uses & applications

Quartz is used in glassmaking, construction, and electronics; mica is used in electrical insulation and cosmetics. This specific specimen is primarily for education or amateur collecting.

Geological facts

Mica can be peeled into paper-thin, transparent sheets. Large sheets of mica were historically used as windows for ovens and woodstoves because of their high heat resistance.

Field identification & locations

Identify in the field by checking if the translucent part can scratch glass (Quartz) and if the dark layers can be flaked off with a fingernail or knife (Mica). Common in mountainous regions with exposed granite or metamorphic bedrock.

Other igneous/metamorphic specimens

See all

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral

Nephrite Jade

Nephrite

Mineral/Rock

Sapphire

Corundum (Al2O3)

mineral

Blue Apatite

Apatite-(CaF), Ca5(PO4)3F (Calcium Fluorophosphate)

mineral

Magnetite

Magnetite (Fe3O4)

mineral

Zoisite with Ruby (Anyolite)

Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)

metamorphic