Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Travertine is a mineral consisting of layered calcium carbonate formed by deposition from spring waters
History
Origin
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Italy
Discoverer
Unknown
Marcus Vitruvius Pollio
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From Italian travertino a kind of building stone, from Tiburs, adjective from Tibur (Tivoli), in Italy
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
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-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock