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N - Jewelry & Gem Dictionary

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NACRE

Nacre is a usually whitish crystalline substance which oysters, mussels, snails, and other mollusks secrete 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

A natural pearl (also called a genuine pearl) is a pearl that was 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 navette is a gemstone which is cut as a marquise.

NECESSAIRE

Necessaire is another word for etui, a tiny, decorative, cylindrical-shaped case that was often carried on a chatelaine. The necessaire/etui was used to carry small "necessary" items like pencils and scissors. The etui was first used in the 1720's.

NECKLACE

A necklace is a peice of jewelry worn around the neck. Necklaces of perals of different lengths have different names: A choker is 14" to 16" long; a princess necklace is 18" long; a matinee necklace is 22" to 23" long; opera is 30" to 35" long; a rope is over 40 " long.

NEPAL DIAMOND

Nepal diamond is a huge flawless, pendeloque diamond that probably came from the Golconda mines in India. The Nepal diamond weighs 80 carats. It was originally owned by the Nepalese government but is now owned by Harry Winston, an American jeweler.

NEPHRITE

Nephrite is a semi-precious stone, a variety of jade (sometimes called greenstone). Two different minerals are known as jade, jadeite and nephrite. Nephrite is slightly softer that jadeite and is often veined; it is used in carvings and for making beautiful bowls and vases.

NEVADA DIAMOND

Nevada diamond is a misleading term for artificially-colored obsidian (a semi-precious stone) - it is not a true diamond

NICKEL SILVER

Nickel silver (also know as German silver) is an alloy consisting of mostly copper (roughly 60 percent), and approximately 20 percent nickel, about 20 percent zinc, and sometimes about 5 percent tin (then the alloy is called alpaca). There is no silver at all in German/nickel silver. This alloy was invented around 1860 in Germany as a silver substitute.

NIELLO

Niello is ancient technique in which an engraved design in metal is filled with powdered niello alloy (a black/dark gray metal alloy composed of silver, copper, lead, and sulphur). The niello alloy is melted (the entire metal piece is heated in a kiln) and it fuses with the underlying metal. The object is then polished - the result is an enamel-like effect. Niello has been made at least since the time of ancient Rome. In older pieces, the niello alloy fills an engraved design in metal. In newer pieces, the nilello forms the backround - the niello alloy is simply "painted" onto the metal (this process is simpler, cheaper, and less durable).

NIGHT EMERALD

Night emerald is a misleading term for peridot (a semi-precious stone) - it is not a true emerald.

NIZAM DIAMOND

The Nizam diamond was a huge Indian diamond that may have weighed from 340 to 440 carats uncut. After being cut into an elongated, convex shape with irregular facets, it was 277 carats. This diamond was owned by the Nizams of Hyderabad in the 1830's. This diamond was "lost" or broken up during a battle.

NOBLE METALS

The noble metals are gold, platinum, and silver. These are metals that are relatively impervious to chemical action.