Clear Quartz (Druzy)
Quartz var. Rock Crystal · Mineral Specimen and Semi-Precious Gemstone
Crystal System
Trigonal system; typically forming as hexagonal prisms with pyramidal terminations, though here appearing as druzy (micro-crystalline) clusters.
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal; formed as silica-rich fluids precipitate and crystallize in rock cavities (vugs) under low to moderate temperatures.
About This Crystal
Clear to translucent small prismatic crystals exhibiting vitreous luster, arranged in a druzy lining throughout a geode-like cavity. The crystals are set against a reddish-brown iron-stained matrix (likely hematite-stained jasper or limonite).
Physical Characteristics
Color: Colorless/White; Streak: White; Cleavage: None (indistinct); Fracture: Conchoidal; SG: 2.65; Fluorescence: Usually inert but can show weak green or yellow under UV.
Optical Properties
Refractive Index: 1.544-1.553; Double refraction (uniaxial positive); Birefringence: 0.009; Weak pleochroism; Vitreous luster.
Hardness & Durability
Origin Region
Common worldwide; notable druzy specimens found in Brazil, Morocco, USA, and Mexico, often within vugs of sedimentary or volcanic rocks.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good (no cleavage); Stable against light and most chemicals except hydrofluoric acid.
Care & Maintenance
Wash with warm soapy water and a soft brush; avoid harsh ultrasonic cleaners if the matrix is porous or crumbly; generally light stable.
Rarity & Value
Common; Value is determined by crystal clarity, sparkle ('druzy' effect), and the overall aesthetic of the contrast against the matrix.
Special Characteristics
Displays a 'druzy' effect where numerous small crystal faces catch the light simultaneously; the host rock shows significant iron oxidation providing the red color.
Lore & History
Quartz has been used since antiquity for carvings and jewelry. In metaphysical traditions, it is known as the 'Master Healer,' believed to amplify energy and clarify thought structures.