mineral

Quartz (Milky/Yellowish)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to pale yellow; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); SG: 2.65

Hardness: 7 on Mohs scale
Color: Translucent white to pale yellow
Luster: Vitreous (glassy) to greasy

Identified July 12, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent white to pale yellow; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); SG: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. Often found in igneous rocks like granite or metamorphic rocks like quartzite. Many specimens in Sri Lanka are found in alluvial gravels (Illama).

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a semi-precious gemstone in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The location provided (Sri Lanka) is famous for 'gem gravels' where water-worn quartz and precious stones are frequently discovered.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. In Sri Lanka, search in riverbeds or gem pits. High-quality transparent quartz is often called 'rock crystal'.