Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Oil Shale is a fine-grained sedimentary rock from which oil is extracted
From Old English scealu in its base sense of thing that divides or separate
Fine Grained Rock, Opaque Rock
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
From the mineral feldspathoid which is the main content of rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock