Druzy Citrine on Sandstone
Quartz (var. Citrine) on Sedimentary Matrix · Mineral Specimen / Decorative Stone
Crystal System
Trigonal crystal system; displays a druzy habit (fine coating of tiny crystals) on a massive matrix.
Mineral Group
Silicates (Subgroup: Tectosilicates)
Chemical Formula
SiO2 (Silicon Dioxide) with trace Fe3+ (Ferric Iron)
Formation Process
Hydrothermal formation where silica-rich fluids precipitate into cavities under moderate temperatures; sedimentary host rock suggests secondary mineralization.
About This Crystal
The specimen features a brown, opaque, sandy-textured matrix with a vug (cavity) containing sparkling, honey-colored druzy crystals. The luster of the crystals is vitreous, while the matrix is dull/earthy.
Physical Characteristics
Color: Golden-brown to tan; Streak: White; Fracture: Conchoidal (crystals) to granular (matrix); Density: ~2.65 g/cm3; Weak or no fluorescence.
Optical Properties
Refractive Index: 1.544-1.553; Double refraction (uniaxial positive); Pleochroism is very weak in citrine; Vitreous luster on crystal faces.
Hardness & Durability
Origin Region
Commonly found in Brazil (Rio Grande do Sul) or Uruguay; typical in volcanic geodes or sedimentary pockets.
Hardness & Durability
Mohs Hardness: 7 (crystals), 5-6 (matrix); High durability for quartz, though druzy surfaces are prone to shedding crystals if struck.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic cleaners which may loosen druzy; keep away from prolonged direct sunlight to prevent color fading.
Rarity & Value
Common; value is determined by the sparkle of the druze and the contrast with the matrix; standard commercial specimen price range $5-$20.
Special Characteristics
Druzy texture provides a 'sugar-coating' effect that creates high surface sparkle; natural citrine is rare, most commercial golden quartz is heat-treated amethyst.
Lore & History
Historically known as the 'Success Stone' or 'Merchant's Stone'; associated with the Solar Plexus chakra. It has been used in jewelry since the Hellenistic Age in Greece.