Granite
Granite (Felsic Intrusive Igneous Rock) · Decorative Stone and Geological Specimen
Crystal System
Varies by mineral component (Feldspars: Monoclinic/Triclinic, Quartz: Trigonal)
Mineral Group
Silicates (Composite Igneous Rock)
Chemical Formula
Composite rock primarily composed of K-feldspar, quartz, plagioclase, and biotite/hornblende
Formation Process
Igneous intrusion formed by the slow crystallization of magma below the Earth's surface
About This Crystal
Tumbled and water-worn pebbles featuring a phaneritic, coarse-grained texture with interlocking mineral crystals of pink potassium feldspar, translucent white to grey quartz, and dark black biotite mica flakes
Physical Characteristics
Colors include pink, grey, white, and black; white streak; uneven or conchoidal fracture; specific gravity around 2.65 to 2.75; generally brittle tenacity; non-fluorescent
Optical Properties
Biaxial optical properties across its constituent minerals; vitreous to dull luster; non-chatoyant
Hardness & Durability
Origin Region
Worldwide distribution; major deposits in Brazil, India, China, Scandinavia, and North America
Hardness & Durability
Composite Mohs hardness of approximately 6 to 7 based on quartz and feldspar components; good durability and high resistance to weathering
Care & Maintenance
Can be easily cleaned with warm soapy water; resilient to standard environmental exposure; avoid harsh industrial acids
Rarity & Value
Common; very abundant across the Earth's continental crust; low to moderate value depending on ornamental polish and decorative quality
Special Characteristics
Exhibits a classic salt-and-pepper or porphyritic flecked texture created by contrasting dark mafic minerals against lighter felsic crystals
Lore & History
Historically used extensively in architecture, monuments, and sculpture due to its incredible strength; in metaphysical traditions, it is believed to promote stability, grounding, balance, and diplomatic cooperation