Milky Quartz with Rock Matrix
Quartz (Alpha) var. Milky Quartz · Mineral Specimen / Decorative Stone
Crystal System
Trigonal; massive/granular habit for this specimen, though typically hexagonal-prismatic in crystal form.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with impurities of graphite or rock matrix (silicates)
Formation Process
Hydrothermal or Igneous; crystallized from silica-rich fluids in rock cavities or during the cooling of molten rock.
About This Crystal
A small, translucent to opaque specimen featuring a milky-white quartz sector attached to a dark grey, fine-grained host rock (matrix). The luster is vitreous on broken surfaces, and the texture is granular.
Physical Characteristics
Color: White and dark grey; Streak: White; Fracture: Conchoidal to uneven; Specific Gravity: 2.65; Tenacity: Brittle; Fluorescence: Generally none.
Optical Properties
Refractive Index: 1.544–1.553; Uniaxial (+); Translucent to opaque; no special optical phenomena like chatoyancy visible in this raw state.
Hardness & Durability
Origin Region
Found globally; common in the Appalachian Mountains (USA), Brazil, and the Alps. Occurs in hydrothermal veins and granite pegmatites.
Hardness & Durability
Mohs hardness of 7 for the quartz portion; Toughness is good; high chemical stability except toward hydrofluoric acid.
Care & Maintenance
Safe to clean with warm soapy water; resistant to sunlight fading. Store away from softer minerals to avoid scratching them.
Rarity & Value
Common; very low market value for small, unpolished, non-crystalline specimens. No common treatments for this basic variety.
Special Characteristics
Contains a distinct contact zone between the silicate quartz and the darker mineral matrix, likely composed of fine-grained schist or shale.
Lore & History
Historically used for making stone tools; in folklore, it is often associated with clarity and the Crown Chakra, though these are traditional rather than scientific claims.