Milky Quartz in Matrix
Quartz (Variety: Milky Quartz) in host rock · Mineral Specimen / Decorative Stone
Crystal System
Trigonal crystal system; displays a massive, granular, and vein-like habit within the matrix.
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2 (Silicon Dioxide) with possible Iron Oxide (Fe2O3) staining
Formation Process
Hydrothermal; forms from silica-rich fluids cooling in rock fractures or cavities, often as veins within igneous or metamorphic host rocks.
About This Crystal
White to off-white translucent milky quartz appearing as veins or pockets within a brown, earthy, opaque matrix. The quartz has a vitreous to greasy luster, while the matrix is dull and granular.
Physical Characteristics
Color: White (quartz), brown/tan (matrix). Streak: White. Cleavage: Indistinct. Fracture: Conchoidal to uneven. Specific Gravity: ~2.65 for quartz. Fluorescence: Generally none.
Optical Properties
Uniaxial positive; Refractive Index: 1.544–1.553. Birefringence: 0.009. The milky appearance is caused by microscopic fluid or gas inclusions.
Hardness & Durability
Origin Region
Globally abundant; notable sources include Brazil, USA (Arkansas), and the Alps. Found in various geological environments like hydrothermal veins.
Hardness & Durability
Quartz has a Mohs hardness of 7. The matrix is likely softer (3-5). Quartz is very durable and stable for most uses, including jewelry.
Care & Maintenance
Safe to clean with warm soapy water and soft brushes. Quartz is resistant to most chemicals but the matrix may be porous and sensitive to acids.
Rarity & Value
Very Common. Found in high abundance globally. Value is low, primarily as a decorative specimen or for educational purposes.
Special Characteristics
Milky appearance due to 'Tyndall scattering' from fluid inclusions; the specimen shows a clear contrast between the hydrothermal quartz vein and the host rock.
Lore & History
Quartz has been used since antiquity for tools and talismans. Milky quartz is traditionally associated with clarity, purification, and calm in various various cultural belief systems.