Quartz (Milky/Clear variety) in Host Rock
Quartz (α-Quartz) · Mineral Specimen / Common Rock-Forming Mineral
Crystal System
Trigonal; typically occurs as hexagonal prisms terminated by rhombohedra. In this specimen, it appears as an irregular, crystalline vug filling or vein fragment.
Mineral Group
Silicates; Tectosilicate (Framework Silicate)
Chemical Formula
SiO2 (Silicon Dioxide)
Formation Process
Hydrothermal or Metamorphic. Likely formed by silica-rich fluids precipitating in a fracture or cavity within the host rock during tectonic activity or cooling magma.
About This Crystal
A small cluster of crystalline quartz embedded in a dark, textured matrix. The crystals range from translucent white (milky) to semi-transparent. The luster is vitreous (glassy) on fresh surfaces, appearing somewhat dull where weathered. The host rock has a grainy, matte appearance.
Physical Characteristics
Color: Colorless to white; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.65; Fluorescence: Generally inert, but may show weak green or yellow depending on localized inclusions.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009 (weakly doubly refractive); Pleochroism: None; Dispersion: 0.013. The specimen shows no special optical phenomena due to its raw state.
Hardness & Durability
Origin Region
Globally ubiquitous; found in metamorphic belts (like the Alps or Appalachians) and igneous terrains. This specific piece is embedded in a fine-grained metamorphic or igneous host rock.
Hardness & Durability
Mohs Hardness: 7. Toughness: Good (brittle but fairly resistant to mechanical stress). Highly stable against household chemicals and light.
Care & Maintenance
Safe to clean with warm soapy water and a soft brush. Keep away from hydrofluoric acid. As an embedded specimen, avoid dropping, as the host rock may crumble or fracture before the quartz does.
Rarity & Value
Common. As a raw field specimen, it holds minimal commercial value, primarily serving as a geological study piece or hobbyist find.
Special Characteristics
None visible in current state. It represents a typical 'in-situ' occurrence of quartz where crystalline growth is constrained by the narrow dimensions of a rock fissure.
Lore & History
Historically used for tools (flint/chert varieties) and ornamentation since the Paleolithic. In metaphysical traditions, clear quartz is considered a 'Master Healer' and is associated with the Crown Chakra for clarity and energy amplification.