cherts
Hard silica stones
Cherts is the plural of chert, a hard, fine-grained sedimentary rock composed mainly of silica.
Cherts form in marine environments and often contain microscopic fossils, making them valuable to geologists studying ancient ocean conditions.
The rock fractures with sharp edges, so prehistoric peoples used cherts extensively for making tools and weapons.
The archaeologists found cherts scattered across the site, evidence of ancient tool-making activity.
Silicon dioxide compound
- quartzCrystalline silicon dioxide
- jasperOpaque colored quartz
- chalcedonyTranslucent microcrystalline silica variety
- agateBanded semiprecious stone
opal · flint · microcrystalline · conchoidal · fracture · hardness · luster · vitreous
Spark-producing sedimentary rock
- arrowheadsSharpened projectile tips
- toolsDevices for doing work
- weaponryMilitary equipment collectively
- handaxeKnapped stone implement
scrapers · blades · cores · flakes · prehistory · Neolithic · Paleolithic · Mesolithic
Atmospheric water deposit
- replacementWhat takes another's place
- hydrothermalHot water underground
- biogenicProduced by organisms
- nodulesSmall rounded protuberances
beds · layers · marine · deep-sea · volcanic · groundwater · dissolution · recrystallization
Study of ancient organisms
- trilobitesExtinct marine arthropods
- ammonitesExtinct coiled-shell cephalopods
- petrificationBecoming rock-like
- fossilizationOrganic remains becoming mineral
diatoms · microfossils · biogenic · preservation · replacement · silicified · casts · molds
silica
Silicon dioxide compound
- quartzCrystalline silicon dioxide
- jasperOpaque colored quartz
- chalcedonyTranslucent microcrystalline silica variety
agate · opal · flint · microcrystalline · conchoidal · fracture · hardness · luster · vitreous · waxy
flint
Spark-producing sedimentary rock
- arrowheadsSharpened projectile tips
- toolsDevices for doing work
- weaponryMilitary equipment collectively
handaxe · scrapers · blades · cores · flakes · prehistory · Neolithic · Paleolithic · Mesolithic · lithic
precipitation
Atmospheric water deposit
- replacementWhat takes another's place
- hydrothermalHot water underground
- biogenicProduced by organisms
nodules · beds · layers · marine · deep-sea · volcanic · groundwater · dissolution · recrystallization · geode
paleontology
Study of ancient organisms
- trilobitesExtinct marine arthropods
- ammonitesExtinct coiled-shell cephalopods
- petrificationBecoming rock-like
fossilization · diatoms · microfossils · biogenic · preservation · replacement · silicified · casts · molds · Cambrian
stratification
Division into distinct levels
limestone · shale · chalk · dolomite · carbonate · marine · deposition · interbedded · lenses · concretions