Granite
Granite (Phaneritic Igneous Rock) · Decorative Stone / Ornamental Rock
Crystal System
Polycrystalline (aggregate of various systems: Trigonal quartz, Monoclinic feldspars)
Mineral Group
Silicates (primarily Tectosilicates)
Chemical Formula
Complex mixture: SiO2 (Quartz) + KAlSi3O8 (Orthoclase) + NaAlSi3O8 (Plagioclase) + (Fe,Mg) silicate minerals (Biotite/Amphibole)
Formation Process
Igneous: Forms from the slow crystallization of magma below Earth's surface (intrusive/plutonic)
About This Crystal
A coarse-grained, phaneritic rock showing a mottled pattern of salmon-pink, grey, and black. It is opaque with a vitreous to dull luster depending on the polish.
Physical Characteristics
Color: Mottled pink, grey, black; Streak: White; Cleavage: None (rock mass), though individual feldspars show cleavage; Specific Gravity: 2.63 - 2.75; Non-fluorescent.
Optical Properties
Usually opaque in mass; individual crystals may show distinct refractive indices (Quartz ~1.54, Feldspar ~1.52). No play of color.
Hardness & Durability
Origin Region
Global; major sources include Brazil, China, India, and the United States (continental crust environments)
Hardness & Durability
Mohs hardness 6 - 7; very high toughness and durability; resistant to most household acids and scratching.
Care & Maintenance
Clean with warm soapy water; avoid prolonged exposure to strong acids which may etch certain mineral components; very stable in sunlight.
Rarity & Value
Common; very abundant in the Earth's crust; value is based on craftsmanship of the carving rather than material rarity.
Special Characteristics
Phaneritic texture (visible crystals); the pink color is specifically due to potassium-rich alkali feldspar.
Lore & History
Historically used as a primary building material for ancient Egyptian pyramids and obelisks; symbolically associated with grounding, endurance, and strength in various folklore traditions.