Granite
Granite (igneous rock composed mainly of quartz, alkali feldspar, and plagioclase) · Mineral Specimen / Igneous Rock
Crystal System
Phaneritic, granular igneous rock composed of multiple crystal systems (Triclinic, Monoclinic, Trigonal)
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
Complex silicate mixture (primarily SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
Formation Process
Igneous process involving slow cooling of silica-rich magma deep beneath the Earth's crust
About This Crystal
A coarse-grained intrusive igneous rock displaying an interlocking texture of pinkish-white feldspar, translucent quartz, and dark black biotite or hornblende flakes, opaque with a vitreous to dull luster
Physical Characteristics
Pink, grey, black, and white coloration; white streak; uneven to conchoidal fracture; no single cleavage plane for the bulk rock; specific gravity approximately 2.65 to 2.75; brittle tenacity
Optical Properties
Composed of minerals with varying optical properties; quartz is uniaxial positive with low birefringence; feldspars are biaxial with lower refractive indices
Hardness & Durability
Origin Region
Worldwide, commonly found in continental shields, mountain cores, and intrusive plutons globally
Hardness & Durability
Overall Mohs hardness around 6 based on constituent quartz and feldspar; excellent durability, commonly used in architecture and monuments
Care & Maintenance
Wash with warm water and mild soap; highly resistant to environmental weathering and standard household chemicals
Rarity & Value
Very common; widely abundant across the Earth's continental crust; low commercial value for standard grades, higher for decorative architectural slabs
Special Characteristics
Displays a classic phaneritic texture with visible interlocked mineral crystals (polymineralic rock aggregate)
Lore & History
Historically used extensively in ancient Egyptian architecture, obelisks, and modern structural engineering; in metaphysical practices, granite is traditionally associated with grounding strength, stability, and enduring resilience