Definition
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
History
Origin
-
-
Discoverer
Unknown
Unknown
Etymology
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock