Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
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