what is the colour of pure marble? what form of rock is marble?
Answers
Answer:
Color: Marble is usually a light-colored rock. When it is formed from a limestone with very few impurities, it will be white in color. Marble that contains impurities such as clay minerals, iron oxides, or bituminous material can be bluish, gray, pink, yellow, or black in color.
Answer:
Marble is a metamorphic rock formed when limestone is exposed to high temperatures and pressures. Marble forms under such conditions because the calcite forming the limestone recrystallises forming a denser rock consisting of roughly equigranular calcite crystals. The variety of colours exhibited by marble are a consequence of minor amounts of impurities being incorporated with the calcite during metamorphism. While marble can appear superficially similar to quartzite, a piece of marble will be able to be scratched by a metal blade, and marble will fizz on contact with dilute hydrochloric acid.
marble
Other specimens - Click the thumbnails to enlarge
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Texture - granular.
Grain size - medium grained; can see interlocking calcite crystals with the naked eye.
Hardness - hard, although component mineral is soft (calcite is 3 on Moh's scale of hardness).
Colour - variable - pure marble is white but marble exists in a wide variety of colours all the way through to black .
Mineralogy - calcite.
Other features - generally gritty to touch.
Uses - building stone; dimension stone for building facings, paving etc; cut into blocks and cut for monuments, headstones etc (wears over time due to softness of calcite, prone to acid rain damage [calcite is soluble in acid]); whiting material in toothpaste, paint and paper.
New Zealand occurrences - Northland (Marble Bay), northwest Nelson (Arthur Marble), Canterbury, Fiordland, Stewart Island.