Granite
Granite (Igneous Rock) · Mineral Specimen / Decorative Stone / Industrial Stone
Crystal System
Varies by constituent mineral (Quartz is Trigonal, Feldspar is Monoclinic/Triclinic, Mica is Monoclinic); massive or granular habit
Mineral Group
Silicates (Composite Rock)
Chemical Formula
Complex silicate rock composed primarily of Quartz (SiO2), Feldspar (KAlSi3O8 to NaAlSi3O8), and Mica (KAl2(AlSi3O10)(F,OH)2)
Formation Process
Igneous intrusive process, forming from the slow cooling and solidification of magma rich in silica and alkali metals deep beneath the Earth's surface
About This Crystal
An igneous rock specimen displaying a phaneritic (coarse-grained) texture with visible interlocked mineral crystals. Shows a mottled mix of grayish-white quartz, opaque lighter feldspar, and dark biotite or amphibole flecks, giving it a speckled salt-and-pepper appearance with a dull to vitreous luster.
Physical Characteristics
Colors range from light gray, pink, to white with dark mineral flecks; white streak; no single cleavage for the rock as a whole due to diverse constituent minerals; uneven to conchoidal fracture; specific gravity around 2.65 to 2.75; brittle tenacity; non-magnetic
Optical Properties
Aggregate optical properties due to multiple minerals; individual quartz and feldspar components exhibit single or double refraction respectively; non-pleochroic overall
Hardness & Durability
Origin Region
Found globally in continental shields, mountain ranges, and intrusive plutons; major deposits in Brazil, India, China, Scandinavia, and the United States
Hardness & Durability
Mohs hardness varies by component from 6 to 7 (dominated by quartz and feldspar); high toughness and exceptional durability, making it highly resistant to weathering and wear
Care & Maintenance
Easily cleaned with warm water and mild soap; highly stable against chemicals and environmental exposure; requires no special storage precautions
Rarity & Value
Extremely common; one of the most abundant rocks in the Earth's continental crust; low monetary value for standard specimens, though decorative dimension stone can vary based on aesthetic quality and source quarry
Special Characteristics
Displays interlocked crystalline texture typical of plutonic intrusive cooling; may sometimes contain accessory minerals like zircon, tourmaline, or garnet
Lore & History
Historically used extensively in architecture, monuments, and sculpture by ancient Egyptians, Romans, and modern builders due to its immense strength. In metaphysical lore, granite is associated with grounding, stability, strength, and protection, though these are traditional beliefs rather than scientific claims.