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Nacre
A crystalline substance, usually whitish in color formed by oysters, mussels, snails, and other mollusks.
They secrete it around a foreign object (like a tiny stone) that has made
its way into their shell. As layers of nacre coat the intruder, a
pearl is formed over a period of many years.
Natural pearl
Also known as a genuine
pearl, is a pearl that is produced in an oyster, freshwater
mussel or other mollusk as a reaction to a tiny invading object
that happened to be caught inside its shell.
Navette
A gemstone.
Nickel Silver
Know as German silver, too, it
is an alloy consisting of mostly copper, and
nickel, zinc, and small quantity of tin.
There is no silver at all in German/nickel silver.
Noble Metals
The term is used for the metals
like gold, platinum, and
silver that are relatively impervious to
chemical action.
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