Nacre: The shiny iridescent substance secreted by a mollusk as a response to an irritant, like a piece of sand. Over time layers of nacre build up to become a pearl.

Naja: (or "Najah") From the Navajo word "Najahe", meaning "crescent". A crescent-shaped silver ornament believed to go back to Moorish designs that was originally a forehead pendant on horse bridles. It is now commonly found pendant from the bottom of a squash blossom necklace.

Navette: See marquise.

Necklace: A form of jewelry worn around the neck. See Bolo, Chain, Choker, Collar, Diva Fashion, Fetish Necklace, Heishi, Hemp, Jocla, Lariat, Lavalier, Length, Matinee Length, Mourning Jewelry, Opera Length, Rivière, Sautoir, Squash Blossom Necklace, Y Necklace.

Needle Point: Stones shaped to a fine point at both ends.

Negligee pendant: See Lavalier.

Neoclassical: New designs inspired by artistic elements from classical antiquity, such as urns, garlands, greek key, palmette.

Nephrite: A compact variety of tremolite and a form of jade. Often called "greenstone" though it can also be found in shades of grey, brown, and black.

Nickel: A hard, bright, silver-white metallic element of the iron group that is malleable, ductile, and resistant to corrosion.

Nickel Silver: An alloy of Nickel, copper, and zinc, which is a white metal but contains no actual silver.

Niello: A black metallic alloy of sulfur, copper, silver, or lead, applied to a metal and fired to create a shimmering black surface. 

Nonmetallic: A material which is not composed of metal.

Non-precious: Any metal that is not considered to be a precious metal or any gemstone that is not considered to be a precious gemstone.

Nose Stud: A simple style of jewelry for pierced nostrils that has a single stone, pearl, or metal ball on a straight post.

Nugget: The term used for a lump, or irregularly shaped mass, of precious metal.