Coral.
Coral
is made up of the skeletal remains of marine animals called
coral polyps. These tiny creatures live in colonies
which form branching structures as they grow, eventually
forming coral reefs and atolls. The surface of these coral
"branches" has a distinctive patterning made by
the original skeleton-either striped or like wood grain.
Most corals- red, pink, white, and blue varieties- are made
of calcium carbonate; black and golden corals are made of a
horn like substance called conchiolin. Red coral is the most
valuable, and has been used in jewelry for thousand of
years. Dull at first, all coral has a vitreous lustre when
polished, but is sensitive to heat and acids may fade with
wear. Coral may be imitated by porcelain, stained bone,
glass, plastic, or rubber and gypsum mixtures.
Occurrence
Most
precious coral is found in warm water. Japanese coral is
red, pink, or white. Red and pink coral is also found on the
Mediterranean and African coasts of the west Indies,
Australia and the Pacific islands.
REMARK
Coral
has been associated with the protection of children, and
parents may still give a gift of coral to their young
children.
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RED
CORAL
CABOCHON
Vivid red
colour
high polish
shows vitreous lustre |
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RED
CORAL
SLICE
Polished
surface
Coss-section
revals intricate banded structure |
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BLACK
CORAL
CABOCHON
Highly polished
surface
Oval cabochon
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IMITATION
CORAL
BEAD
Polished bead
manufactured by Gilson of france to imitate dark
pink coral |
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