Granite
Granite (Felsic Intrusive Igneous Rock) · Decorative Stone and Mineral Specimen
Crystal System
Multisystem (Aggregate of Triclinic/Monoclinic Feldspars, Trigonal Quartz, and Monoclinic Micas)
Mineral Group
Silicates (Framework silicates and sheet silicates)
Chemical Formula
Complex silicate mixture: (K,Na)AlSi3O8 (Feldspar) + SiO2 (Quartz) + KAl2(AlSi3O10)(F)(OH) or similar (Mica)
Formation Process
Igneous process involving slow cooling and crystallization of magma rich in silica, potassium, and sodium beneath the Earth's surface.
About This Crystal
Coarse-grained intrusive igneous rock displaying a phaneritic texture with interlocking crystals of pinkish-red alkali feldspar, translucent quartz, and dark biotite or amphibole minerals, creating a speckled mosaic appearance.
Physical Characteristics
Colors include pink, red, grey, and white with black speckles. Streak is white. Fracture is uneven to conchoidal. Specific gravity is approximately 2.65 to 2.75. Tenacity is brittle. Non-magnetic and lacks significant fluorescence.
Optical Properties
Aggregated optical properties reflecting its constituent minerals. Refractive indices range from approximately 1.53 to 1.55. Doubly refractive for individual crystal components. Non-pleochroic as a bulk rock.
Hardness & Durability
Origin Region
Found globally in continental crust; notable sources include Brazil, India, China, Scandinavia, and North America. Forms in intrusive igneous environments.
Hardness & Durability
Mohs hardness ranges from 6 to 7 based on the constituent quartz and feldspar minerals. Excellent durability, highly resistant to weathering, and widely used for architectural and decorative purposes.
Care & Maintenance
Clean with warm water and mild soap. Avoid harsh chemical cleaners and acids. High durability allows for easy maintenance.
Rarity & Value
Extremely common globally. Value depends on slab aesthetic quality, color uniformity or uniqueness, and dimension size for commercial use. Common decorative and building stone.
Special Characteristics
Interlocking crystalline texture providing high compressive strength and distinctive visual speckling known as salt-and-pepper or pink-granite patterning.
Lore & History
Historically used extensively in ancient architecture, sculpture, and monumental construction (e.g., Ancient Egyptian pyramids and temples). In modern metaphysical lore, granite is associated with grounding, stability, strength, and fostering diplomatic relationships.