Granite

Hardness: 6-7 on Mohs scale. Color: Typically white, pink, or gray, with dark mineral speckles (often black). Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained, crystals visible to the naked eye). No distinct cleavage planes for the rock as a whole, but individual mineral components have cleavage. Specific Gravity: 2.65 - 2.75.

Granite is an intrusive igneous rock, meaning it formed from the slow crystallization of magma below Earth's surface. It forms from the cooling of highly felsic (silica-rich) magma. The slow cooling allows for the formation of large, interlocking mineral crystals. It is typically associated with continental crust formation and can be found in ancient mountain ranges and cratons, often forming during orogenic events (mountain building episodes) over millions of years.

Industry: Widely used in construction for countertops, flooring, paving, and building facades due to its durability, strength, and aesthetic appeal. Construction: Dimension stone, crushed stone for road aggregate. Jewelry: Not typically used as a gemstone, but polished slices can be used in ornamental items. Other: Monuments, gravestones.

Granite is one of the most common intrusive igneous rocks on Earth's continental crust. Its name comes from the Latin word 'granum', meaning 'grain', in reference to its coarse-grained structure. It is resistant to weathering and erosion, making it a very durable material.

To identify in the field, look for a coarse-grained, interlocking texture where individual mineral crystals (quartz, feldspar, mica) are clearly visible with the naked eye. The color is usually a combination of light (white, pink, gray) and dark (black) minerals. It is very hard and will resist scratching by a steel nail. Common locations: Found in continental shield areas, ancient mountain ranges, and batholiths worldwide. Major producers and regions include the United States (e.g., Vermont, North Carolina), India, Brazil, Norway, and China. Tips for collectors: Look for fresh exposures in quarries or riverbeds. Examine the proportions and types of mineral crystals to better understand its composition.