Glossary N-S

A-B ~ C-D ~ E-H ~ I-M ~ T-Z ~ Glossary TOC

obsidian	Obsidian is volcanic glass formed when hot lava cools quickly. A Roman named Obsius is said to have discovered the stone in Ethiopa, and obsidian was highly prized in antiquity for its sharp edges and glossy luster. Snowflake obsidian is black obsidian with flakes of volcanic ash that resemble snowflakes.
opal	Opal is a member of the quartz group. The name is from an Indian word meaning simply "stone". Three types are precious opal, with a rainbow iridescence, fire opal, named for its red-orange color, and common opal which lacks the iridescence of precious opal.
padre beads	Beads used by the missionary monks and friars. Many of the antique Dutch glass beads that have survived are the ones from their rosaries, which often times were traded by the good monks for drink. See prayer beads.
pearl	A pearl is formed when a bit of sand or other irritant gets inside the shell of a mollusk, such as an oyster. The mollusk secretes calcium carbonate to surround the irritant, which accumulates in layers of aragonite and conchiolin. This layered formation causes the refraction of light that gives pearls their distinctive appearance. Colors vary with the type of mollusk, and varying nutrients in the water.
pearl, simulant	I use South Ocean^® simulated pearls which have layers of plastic "nacre" over a stone nucleus. It gives the illusion of a fine quality Tahitian black pearl, or cultured white pearl at a fraction of the cost.
peridot	A gem variety of the mineral olivine. Peridot has been connected with various superstitions throughout history. It has been associated with the sun, and was believed to be able to break evil spells. During the Middle Ages, it was worn to gain foresight and divine inspiration. It's found by the Red Sea in Aswan, and in Burma,
pleochroism	When light passes through a doubly refractive gemstone, the light is split into two rays which are polarized at right angles to each other and travel at differing velocities through the gemstone. In some colored doubly refractive gemstones, these rays may emerge differing in shade or color. When this occurs, the rays are said to have experienced "Differential Selective Absorption".
prayer bead	Many of the beads created by the Dutch and Venetian glassmakers were used in rosaries, like the" white cross"beads in the Rosary item f011. Chevron beads used in cardinal's rosaries were called rosarios.
quartz	Quartz (silicon dioxide,SiO2) is the most common mineral on Earth. It is found in nearly every geological environment and is at least a component of almost every rock type. It is also the most varied in terms of varieties, colors and forms. This variety comes about because of the abundance and widespread distribution of quartz.
retticello	The delicate latticework of white glass as created by the Moretti family. See Moretti
rose bead	Originally a Venetian pattern of bead called such because of the "rose" of glass. Also called a fiorato in Italian. Both the Bohemians and Indians make a rose or fiorato bead, although the finest by far is the Venetian.
rose quartz	Named for its color, it is said that rose quartz should only be given as a gift to one's true love. See Quartz.
rutilated quartz	Clear to opaque shades of yellow, the golden rutile crystals have a near metallic luster. If quartz is heat-treated, which is often done to achieve a more uniform color, then the rutile will burn away. Rutilated quartz is not as common as other types of quartz.
sand-cast	Technique for making glass beads in Ghana, using powdered or pulverized glass cast in sand, giving the beads a grainy rather than smooth finish.
sapphire	A gemstone variety of the corundum family. Generally all colors of corundum except red (ruby) are called sapphires.
satina bead	Refers to the finish on some modern Bohemian glass beads, as opposed to the fire polish on Bohemian crystal beads.
serpentine	It is a very pretty light green transluscent gemstone, often mistaken for jade or alabaster.
Sputnik beads	A Bohemian glass bead, called such because they were first made in the late 1950's to commemorate the Russian Sputnik satellite.Sputnik beads are the most signifigant bead of the 20th century, because it is the only bead created in over a century to comemmorate a major event in human history.

More terms will be added as time goes by. I welcome questions, comments or even corrections by email.