Druzy Quartz on Matrix
Quartz variety Druzy on Quartzite/Chert matrix · Mineral Specimen / Decorative Stone
Crystal System
Trigonal; typically appears as micro-crystalline druse (tiny crystals coating a surface) or as a massive matrix.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide)
Formation Process
Hydrothermal; forms when silica-rich fluids precipitate into cavities or over existing rock surfaces at relatively low temperatures.
About This Crystal
The specimen features a dark, greyish-green basaltic or chert-like matrix with small vugs (cavities) containing tiny, sparkling white to translucent 'druzy' quartz crystals. Portions of the rock show yellowish-brown iron staining (limonite) and a dull to vitreous luster.
Physical Characteristics
Color: Grey-green matrix with white inclusions; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.65; Fluorescence: Generally inert but can show weak green or yellow under UV.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; Optical Character: Uniaxial (+); Phenomena: Scintillation (sparkling effect from many tiny crystal faces).
Hardness & Durability
Origin Region
Worldwide; commonly sourced from Brazil, Uruguay, and the United States (Missouri, Arizona). Often found in limestone or volcanic cavities.
Hardness & Durability
7.0 on Mohs scale. While the mineral is hard, the druzy surface is fragile and prone to 'shedding' tiny crystals if bumped or scratched.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners as they can vibrate the druzy crystals loose from the matrix. Store away from harder stones to prevent scratching.
Rarity & Value
Common; Value is generally low ($10-$50 for small hand samples) unless the crystals are rare colors or the matrix contains precious metals.
Special Characteristics
The sparkling 'sugar-like' texture of the druzy coating and the presence of small botryoidal or vuggy formations within the matrix rock.
Lore & History
Historically, quartz has been used for tool-making and ritual objects across all continents. Metaphysically, quartz is often associated with the Crown Chakra and believed to amplify energy and provide mental clarity.