Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
History
Origin
Pennsylvania, U.S.
-
Discoverer
Unknown
Unknown
Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock