1 Definition
1.1 Definition
Basalt is a common extrusive igneous rock formed by the rapid cooling of basaltic lava exposed at or very near the surface of Earth
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
1.2 History
1.2.1 Origin
1.2.2 Discoverer
Georgius Agricola
Unknown
1.3 Etymology
From Late Latin Basaltes (variant of basanites ), very hard stone, which was imported from Ancient Greek Basanites
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
1.4 Class
Igneous Rocks
Sedimentary Rocks
1.4.1 Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock