Flint
Quartz var. Flint · Mineral Specimen and Historical Tool Material
Crystal System
Trigonal, microcrystalline massive habit
Mineral Group
Silicates, Tectosilicate subgroup
Chemical Formula
SiO2
Formation Process
Sedimentary formation through the chemical replacement of calcium carbonate by silica-rich solutions within chalk or limestone beds
About This Crystal
An opaque, dull to waxy luster rock composed of microcrystalline quartz with mottled grey, brown, and white coloration, showing conchoidal fracture edges
Physical Characteristics
Grey to dark brown body color with white patches, white streak, conchoidal fracture, no cleavage, specific gravity of approximately 2.60 to 2.65, brittle tenacity
Optical Properties
Microcrystalline aggregate exhibiting aggregate birefringence under polarized light, singly or doubly refractive under micro-analysis but generally appears non-optic in megascopic view due to cryptocrystalline nature
Hardness & Durability
Origin Region
Found worldwide in chalk and limestone formations, particularly notable in Western Europe, the United States, and the UK
Hardness & Durability
Mohs hardness of 7, high toughness due to microcrystalline structure making it resistant to impact, excellent durability for weathering
Care & Maintenance
Can be cleaned safely with warm soapy water and a soft brush, highly resistant to chemicals and stable in sunlight
Rarity & Value
Common, widely distributed globally with low commercial monetary value, though prized by knappers and historical artifact collectors
Special Characteristics
Produces sparks when struck against steel due to its hardness and microcrystalline friction, traditionally used for fire-starting
Lore & History
Extensively used by ancient humans for making stone tools, arrowheads, and blades during the Stone Age, later utilized in flintlock firearms; associated traditionally with grounding, protection, and cutting away emotional cords