Quartz Vein in Basalt or Slate
Quartz Vein in Metamorphic/Igneous Host Rock · Mineral Specimen / Geological Specimen
Crystal System
Trigonal (Quartz) / Massive or Cryptocrystalline for host rock; habit is water-worn pebble with hydrothermal vein inclusion.
Mineral Group
Silicates (Tectosilicate for quartz)
Chemical Formula
SiO2 (Quartz) with variable host rock composition (silicates, iron oxides)
Formation Process
Hydrothermal activity filling fractures in host rock (igneous or metamorphic) with silica-rich fluids, followed by weathering, erosion, and aqueous transport.
About This Crystal
An asymmetrical, water-worn pebble or cobble featuring a dark grey to charcoal host rock matrix intersected by a prominent, whitish-beige crystalline quartz vein running diagonally across the stone. The surface is smooth and polished from fluvial tumbling, displaying slight dampness or natural luster. A small vug or cavity is visible within the quartz vein.
Physical Characteristics
Dark grey host rock with white to off-white quartz vein; streak is white; cleavage is none in quartz (conchoidal fracture), distinct cleavage or parting may exist in host; specific gravity around 2.65 for quartz portion; brittle tenacity.
Optical Properties
Quartz is uniaxial positive with low birefringence; host rock is opaque and non-reflective; vitreous luster on the quartz fracture surfaces, dull to sub-vitreous on the host rock exterior.
Hardness & Durability
Origin Region
Found globally in riverbeds, glacial tills, and coastal beaches where quartz-veined rocks have undergone water-transport and rounding.
Hardness & Durability
Quartz has a Mohs hardness of 7, while the surrounding host rock (if basalt or slate) typically ranges from 3 to 6; overall durable due to water-worn smoothing.
Care & Maintenance
Wash with warm soapy water and a soft brush; store away from softer minerals to prevent scratching; chemically inert to common household cleaners.
Rarity & Value
Common; ubiquitous geological specimen with minimal commercial value, valued primarily for educational or decorative interest.
Special Characteristics
Contains a distinct hydrothermal quartz vein cutting through a darker matrix, highlighting structural geology concepts like fault-filling or fracture-filling mineralization.
Lore & History
Often viewed in crystal lore as a stone of integration, symbolizing the bridging of opposites or the flow of energy through barriers; traditionally associated with clarity and grounding, though these are non-scientific cultural beliefs.