Definition
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
History
Origin
-
-
Discoverer
Unknown
Unknown
Etymology
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Family
Group
Volcanic
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Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock