Definition
Mudstone is a fine-grained, dark gray sedimentary rock, which is formed from silt and clay and is similar to shale but has less laminations
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
History
Origin
-
-
Discoverer
William Smith
Unknown
Etymology
From the English mud and stone, from low German mudde and stainaz
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock