Flint
Quartz var. Flint · Mineral Specimen
Crystal System
Trigonal, microcrystalline habit forming nodules and masses
Mineral Group
Silicates
Chemical Formula
SiO2
Formation Process
Sedimentary formation through the chemical replacement of calcium carbonate by silica in marine environments
About This Crystal
Small, water-worn pebble showing an opaque, gray-to-brownish hue with a smooth, tumbled exterior and dull to waxy luster
Physical Characteristics
Gray to dark brown body color, white streak, conchoidal fracture, no cleavage, specific gravity of approximately 2.60 to 2.65, brittle tenacity
Optical Properties
Microcrystalline aggregate displaying aggregate birefringence and a dull or waxy luster
Hardness & Durability
Origin Region
Found worldwide in chalk and limestone formations, notably Western Europe and North America
Hardness & Durability
Mohs hardness of 7, high durability and toughness due to its interlocking microcrystalline quartz structure
Care & Maintenance
Can be cleaned with warm soapy water and a soft brush; highly durable with no special chemical sensitivities
Rarity & Value
Very common mineral, low economic value primarily collected as a historical tool-making material or geological specimen
Special Characteristics
Historically noted for its ability to produce sparks when struck against steel due to its high hardness and conchoidal fracture
Lore & History
Historically significant in human evolution for the creation of sharp stone tools, arrowheads, and fire-starting flintlock mechanisms