Quartz-Rich Metamorphic Rock with Muscovite Mica
Quartzite with Muscovite (Silica var. Quartz) · Mineral Specimen / Decorative Stone
Crystal System
Trigonal (Quartz) / Monoclinic (Muscovite). Exhibit a massive, granular, and foliated habit.
Mineral Group
Silicates (Tectosilicate for Quartz; Phyllosilicate for Mica)
Chemical Formula
SiO2 with KAl2(AlSi3O10)(OH)2 (Muscovite) and trace iron oxides (Fe2O3)
Formation Process
Metamorphic; formed from the recrystallization of sandstone (quartzite) or regional metamorphism of pelitic rocks (schistose textures).
About This Crystal
The specimen features a granular, crystalline surface with a reddish-brown to tan matrix. It shows distinct vitreous to pearly luster where small mica flakes reflect light. The texture is rough and sugary (saccharoidal) with visible inclusions of darker iron oxides.
Physical Characteristics
Color: Reddish-brown, tan, and white. Streak: White. Cleavage: None in quartz; perfect basal cleavage in mica flakes. Fracture: Conchoidal to uneven. Specific Gravity: 2.6-2.7. Non-fluorescent.
Optical Properties
Low birefringence; typically transparent to translucent in individual grains. The mica flakes show pearly luster and high reflectivity (sheen).
Hardness & Durability
Origin Region
Found globally in metamorphic belts; notably Brazil, India, and the Appalachian or Himalayan ranges.
Hardness & Durability
Mohs Hardness: 6.5 to 7 (dominated by Quartz). High toughness and excellent durability for outdoor or decorative use. Muscovite flakes are soft (2.5) and can be scratched easily.
Care & Maintenance
Clean with warm soapy water. Avoid hydrofluoric acid. Generally stable in sunlight and resistant to physical weathering.
Rarity & Value
Common. Value is primarily aesthetic or industrial; inexpensive as a mineral specimen unless showing rare crystal habits or mineral associations.
Special Characteristics
Presence of 'micaceous sheen' or 'schistosity' where flat mica minerals align. Small reddish iron oxide patches create a natural variegated appearance.
Lore & History
Quartz has been used since prehistory for tools and ritual objects. Historically associated with clarity and energy amplification. Micas were used in ancient times as windows (muscovy glass) before the prevalence of industrial glass.