Granite
Plutonic Igneous Rock · Mineral Specimen / Igneous Rock
Crystal System
Phaneritic, granular texture; composed of multiple mineral systems including triclinic, monoclinic, and hexagonal
Mineral Group
Silicate Rock Aggregate
Chemical Formula
Complex silicate mixture (primarily SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8, with biotite and amphibole)
Formation Process
Igneous plutonic formation from the slow, deep-seated cooling of silica-rich magma beneath the Earth's crust
About This Crystal
A coarse-grained igneous rock displaying an interlocking mosaic of mineral crystals, primarily light-colored quartz and feldspar interspersed with darker biotite mica and amphibole grains, showing a mottled grey, white, and brownish-black appearance with a rough, crystalline surface texture.
Physical Characteristics
Colors range from white and grey to pink and black; streak is white; irregular to uneven fracture; specific gravity ranges from 2.65 to 2.75; high tenacity; generally non-magnetic though accessory magnetite may cause weak localized attraction
Optical Properties
Varies by constituent minerals; quartz and feldspar show typical refractive indices around 1.54 to 1.55; aggregate displays mixed luster and no uniform single optical phenomenon
Hardness & Durability
Origin Region
Found globally in continental shields, mountain cores, and intrusive plutons worldwide
Hardness & Durability
Overall Mohs hardness of approximately 6 due to quartz and feldspar constituents; high durability, excellent resistance to weathering, abrasion, and mechanical wear, making it exceptionally well-suited for architectural and structural uses
Care & Maintenance
Requires minimal maintenance; can be cleaned safely with warm soapy water and a soft cloth; resistant to most household chemicals, though acidic solutions can affect certain accessory minerals over prolonged exposure
Rarity & Value
Extremely common globally; value is determined primarily by decorative aesthetic appeal, slab size, and uniformity for dimensional stone and monumental use rather than mineral rarity
Special Characteristics
Interlocking crystalline texture provides exceptional structural strength; presence of accessory minerals such as zircon, tourmaline, or garnet occasionally adds localized point-specimen interest
Lore & History
Historically utilized by ancient Egyptians and Romans for monumental architecture, obelisks, and structural columns. In modern metaphysical practices, granite is traditionally associated with grounding energy, strength, stability, and fostering emotional balance and resilience, though these remain cultural and traditional beliefs rather than scientific attributes