1 Definition
1.1 Definition
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
1.2 History
1.2.1 Origin
1.2.2 Discoverer
Unknown
Christian Leopold von Buch
1.3 Etymology
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
From Latin glaber bare, smooth, bald
1.4 Class
Sedimentary Rocks
Igneous 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
Coarse Grained Rock, Opaque Rock