Definition
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Etymology
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Other Categories
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Fine Grained Rock, Opaque Rock
Jaspillite is an iron rich chemically formed rock which is common in banded iron formation rocks
Western Australia, Minnesota
From Jaspilite (Mineral), a compact siliceous rock which resembles jasper
Coarse Grained Rock, Opaque Rock