Pennyweight
A measure used to weigh precious metals of gold, platinum and silver, a pennyweight (abbreviated dwt.) is equal to 24 grains and there are 20 pennyweights in a Troy ounce.

Peridot
Peridot (also known as the "evening emerald" and chrysolite) is a yellow-green semi-precious stone with an oily luster; peridot is a transparent, green form of olivine. Peridot exhibits double refraction; when you look through the stone, things appear double. For example, when looking into a faceted peridot gemstone, the number of bottom facets appears to be double the actual number of facets. Most peridots are from a volcanic island in the Red Sea, Zebergit/St. John, the "Serpent Isle." Peridots have been found in meteorites. Peridot has a hardness of 6.5. Peridot cat's eye also exists.

Perfuerfumeds
Beads that release a scent when warmed by the body.

Petit Point
A stone shaped to a fine point which is usually somewhat larger than needle point and is characterized by being round, oval, or having one rounded end.

Palamette
A stylized palm leaf which is a common motif in Greek and Persian art.

Petrified Wood
Petrified wood (also called xyloid jasper or jasperized wood) is wood that has fossilized - all the original chemicals in the wood have ben replaced with minerals, making a stone-like replica of the original wood.

Pewter
Peweter is an metal alloy that is composed mostly of tin combined with lead, antimony, bismuth, copper, and/or silver (the formulation varies quite a bit). When pewter is polished it has a silvery luster. Most pewter is over 90 percent tin. Pewter is a soft alloy that is worked by casting, hammering, or turning.

Phenacite
A glassy, colorless mineral occuring in rhombohedral crystals composed of beryllium silicate. From the Greek for imposter, deceiver, phenacite is a silicate of glucina, and receives its name from its deceptive similarity to quartz. It is sometimes used as a gemstone.

Phosphate
A salt composed of the most highly oxidized acid of phosphorus, and forms an important and extensive series of compounds.


Phosphorus
A highly reactive, poisonous, nonmetallic element occurring naturally in phosphates, especially apatite, which is found as a white, or yellowish, translucent waxy substance, having a characteristic disagreeable smell and a faint glow.

Picture Jasper
An opaque tan colored variety of jasper with medium and dark brown patches that make the "pictures."

Piddiddly Links
Pididdly Links is a costume jewelry company that was formed in 1969 in Lake Katrine, New York. Pididdly Links creates antique reproduction pieces (including pins, earring, necklaces, bracelets, and barrettes) in Victorian, Art Nouveau, and other decorative stlyes. The jewelry mostly has a gold-tone finish and Swarovski crystals.

Pierced
A hole punched completely through an object.

Pierced Work
Pierced work is jewelry (or other metal work) that has patterns cut out of the metal. Pierced work is done with a piercing saw, a tiny chisel, or a stamping machine (with a die as the pattern). When a saw is used, the pattern is drawn on the metal, then a small hole is drilled in each of the future holes. The saw is then used to cut out the desired areas.

Pietra Dura
Pietra dura (meaning "hard rock") is an ancient technique of inlaying semi-precious stones (like alabaster, agate, onyx, lapis lazuli, jasper, topaz, and carnelian) into marble or other soft stone. This art form superficially resembles mosaics.

Pigeon's-Blood
A deep red-violet shade of ruby which is the most desirable color of ruby.

Pin
A pin (also brooch) is an ornament that can be pinned to a garment. The pin above is by Trifari.

Pinchbeck
Pinchbeck (also known as "false gold") is a alloy of copper that looks like gold. Pinchbeck was invented by the British watchmaker Christopher Pinchbeck (1672-1732) in the early 18th century. Pinchbeck consists of 83% copper and 17% zinc. Ironically, there have been many imitations of Pinchbeck (which itself is an imitation).

Pink Gold
Pink gold (also known as rose gold) is gold with a tinge of pink. It has been alloyed with a mix of 90% copper and 10% silver.

Pink Topaz
Pink Topaz (Aluminum silicate fluoride hydroxide) is a very hard pink gemstone. Pink topaz is usually created by irradiating common yellow topaz. Topaz has a hardness of 8 and a specific gravity of 3.5-3.6.

Pique
Pique is a tortoise shell inlaid with precious metal (usually gold or silver). Pique is made by inserting hot metal into the tortoise shell; the hot metal melts the shell upon contact.

Plain
An object with one plain uniform color and no decorations of any kind.

Peking Jade
Peking jade is the same as jade, but often refers to nephrite.

Plane of Symmetry
A plane of symmetry is a plane that divides a solid into two mirror-image pieces of the solid.

Plagioclase
Another name for Oligoclase.

Plating
Plating or electroplating (also called Galvanotechnics after its inventor, Luigi Galvani) is a process in which one metal is coated with another metal using electricity. In jewelry, inexpensive metals are frequently electroplated with more expensive metals, like gold (gold plating), copper (electrocoppering), rhodium (rhodanizing), chromium (chromium plating), or silver (silver plating). The thickness of the metal coat varies. Electrogilded coating is the thinnest (less than 0.000007 inches thick); gold-cased metals have a coating thicker that 0.000007 inches.

Platinum
Platinum is a very strong, dense precious metal with a white color. Platinum jewelry is usually 90%-95% pure, is very sturdy, and holds stones well; to strengthen the metal and increases the workability of the platinum, platinum is usually alloyed with 5 to 10 percent of another platinum group metal (like ruthenium, palladium, or iridium) and/or cobalt. Platinum is 60% heavier than gold. Platinum was only discovered in the 1700's in Russia. Platinum is abbreviated Pt. and Plat.

Platinum Group Metaks
The Platinum Group Metals (abbreviated PGM) are the precious metals platinum, iridium, palladium, ruthenium, rhodium, and osmium. They are all rare (platinum and palladium are the most common) and expensive; they are also often found together in nature.

Pleochroism
Pleochroism is the property of having more than two colors, especially when viewed from different angles. In pleochroic minerals, a single stone will show many colors (in the case of Iolite, violet-blue, light blue, and yellow-gray will be visible).

Point
A point is a hundredth of a carat or 0.002 gram.

Poison Ring
A small hinged box secured to a ring which is made to resemble a normal setting, but can be opened to reveal a small space which could conceivably be used to hold poison. See also Prayer ring.

Poison Pendant
A small box worn as a pendant that could conceivably be used to hold poison. See also Prayer pendant.

Polish
Literally meaning "many colored", in the context of jewelry it simply refers to a decoration that uses three or more colors.