Granite
Granite (Igneous Rock / Mineral Aggregate) · Mineral Specimen / Decorative Stone / Industrial Mineral
Crystal System
Varies by constituent minerals (Quartz is Trigonal, Feldspars are Monoclinic/Triclinic); massive, granular habit
Mineral Group
Silicates (Composite Rock)
Chemical Formula
Complex silicate rock composed primarily of Quartz (SiO2), Alkali Feldspar (KAlSi3O8), and Plagioclase Feldspar ((Na,Ca)Al(Si,Al)3O8), with accessory micas
Formation Process
Igneous intrusive process, slowly cooling from silica-rich magma deep beneath the Earth's surface under high pressure
About This Crystal
Coarse-grained intrusive igneous rock displaying a phaneritic texture with visible interlocking mineral crystals of quartz, feldspar, and dark micas, showing a mottled grey, brown, and speckled appearance
Physical Characteristics
Colors range from pink to grey and white depending on feldspar content; white streak; no overall cleavage for the rock though individual minerals exhibit cleavage; uneven, splintery fracture; specific gravity around 2.65 to 2.75; brittle tenacity
Optical Properties
Varies by individual constituent mineral grains; quartz and feldspar are transparent to translucent individually, displaying aggregate reflection and vitreous luster
Hardness & Durability
Origin Region
Found worldwide in continental crust; major sources include Brazil, India, China, Scandinavia, and North America
Hardness & Durability
Overall Mohs hardness of approximately 6 due to quartz and feldspar components; highly durable, resistant to weathering, and excellent for structural and decorative wear
Care & Maintenance
Clean with mild soap and warm water; avoid harsh acidic chemicals that can etch certain accessory minerals; very stable and resistant to environmental factors
Rarity & Value
Very common; widely available globally as a primary component of continental crust, with value dependent on decorative slab aesthetics rather than mineral rarity
Special Characteristics
Composed of an interlocked mosaic of multiple distinct mineral species, often exhibiting pegmatitic phases or graphic granite textures
Lore & History
Historically used extensively in ancient architecture, monuments, and sculpture due to its exceptional strength and durability; in modern crystal lore, it is sometimes associated with grounding, stability, and strengthening resilience, though these are traditional beliefs