Quartz with Pyrite Inclusions
Quartz var. Milky Quartz with Pyrite · Mineral Specimen
Crystal System
Trigonal, massive and anhedral crystal habit embedded in host rock
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2 with FeS2
Formation Process
Hydrothermal vein formation, where silica-rich aqueous solutions deposit quartz alongside sulfide minerals at moderate temperatures and pressures
About This Crystal
A close-up view of a coarse-grained quartz matrix showing translucent to opaque greyish-white quartz surfaces, interspersed with metallic, brassy pyrite flecks and micro-crystals glittering across the uneven fracture planes
Physical Characteristics
Color ranges from grey-white to clear with metallic brass-yellow spots; streak is white for quartz and greenish-black for pyrite; conchoidal to uneven fracture; specific gravity approximately 2.65 for quartz and 5.0 for pyrite; brittle tenacity; no significant cleavage
Optical Properties
Singly refractive (isotropic) properties not applicable to the aggregate, but quartz is uniaxial positive with a refractive index around 1.544-1.553; pyrite exhibits a metallic opaque luster with strong reflectance
Hardness & Durability
Origin Region
Found globally; notable deposits in the USA, Brazil, and Madagascar within hydrothermal veins and pegmatites
Hardness & Durability
Mohs hardness of 7 for quartz and 6-6.5 for pyrite; good durability for general display, though softer inclusions and brittleness require gentle handling
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh acids that can damage the iron sulfide (pyrite) components and keep away from prolonged direct sunlight
Rarity & Value
Common mineral specimen; value depends on the aesthetic distribution of pyrite crystals within the quartz matrix, typically ranging from affordable to moderately priced for collectors
Special Characteristics
Displays brilliant metallic flashes from finely disseminated pyrite grains scattered across a translucent quartz matrix, creating a star-dust or glitter effect
Lore & History
Quartz is traditionally viewed as a master healer stone that amplifies energy and clarity, while pyrite is associated with abundance, vitality, and willpower; these properties are traditional beliefs rather than scientific claims