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
Teschenite is coarse- to fine-grained, dark-coloured intrusive igneous rock that usually occurs in sills, dikes and irregular masses and is always altered to some extent
From its occurrence near Teschen. now known as Cieszyn, Pol., Scotland
Coarse Grained Rock, Opaque Rock