Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components
History
Origin
-
Southern Alps, France
Discoverer
Unknown
Jakob Sederholm
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From the Greek word migma which means a mixture
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock