Glossary - Rarity4u

Home

Glossary

Antiques & Collectables
Glossary of antique and collectable terms

There are 856 entries in this glossary.

All | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Page: 1 2 3 Next »

R

Term	Definition
Radiant Cut	The radiant cut is a method of cutting rectangular stones so that they have the sparkle of brilliant cut round stones. The shape is a rectangle with the corners clipped off - the length:width ratio is usually from 1.5:1 to 1.75:1. This cut has from 58-70 facets; it was invented in the 1970's. The top of the stone is emerald cut (with about 25 facets above the girdle), but the bottom of the stone has brilliant cut facets (with about 36 facets below the girdle)
Rainbow Calsilica	Rainbow calsilica is a newly-found, multi-coloured, layered stone composed of calcium and silica. This stone has been recently used for Zuni fetish carvings and in some jewellery (beads and cabochon cut stones). Rainbow calsilica was only recently found in Mexico or Northern South America (it's origin remains mysterious). Some people theorize that this stone formed as a result of the run off of mining or oil-drilling chemicals, and has only formed in the last 30 to 50 years but this is uncertain.
Rainbow Obsidian	Rainbow obsidian is another name for obsidian that is iridescent
Rainbow Opal	Rainbow opal is a type of precious opal that has curved bands of colors (that resemble rainbows)
Rainbow Topaz	Rainbow topaz, also called mystic topaz or mystic fire, is topaz that has been colour enhanced by coating it with a fine layer of metal atoms in a process called vacuum deposition. This stone has red, green, violet, and blue streaks. Mystic fire has a hardness of 8
Raising	Process by which a piece of hollow ware is hammered into shape, using annealed silver.
Rajaranta	The Rajaratna is the biggest-known "star ruby" (a ruby that exhibits an asterism, a six-pointed star of light, cut as a cabochon). It weighs 2,475 carats
Rajaratna	The Rajaratna is the biggest-known "star ruby" (a ruby that exhibits an asterism, a six-pointed star of light, cut as a cabochon). It weighs 2,475 carats.
Rati	The rati is an Indian unit of weight that is used for gemstones. A rati is equal to 0.91 carats. The rati has varied in the past (and in different regions).
Rat’s Tail	Short ridge of silver applied to the back of spoon bowls to reinforce the joint at the handle
Raviratna	The Raviratna is the biggest-known ruby. It weighs 3,600 carats
Reconstructed Stone	A reconstructed stone is one that is made from pieces of smaller stones or crystals. Reconstructed stones often have telltale air bubbles. For example, Geneva rubies, that are reconstructed rubies, are made from tiny ruby crystals that have been fused together. This type of stone is generally no longer manufactured, except reconstructed amber, which is still made because synthetic stones are vastly superior to reconstructed stones.
Red Beryl	Red beryl is a rare, deep red variety of beryl. Gemstone-quality forms of this mineral are found in only one place in the world, in the Wah Wah Mountains, near Beaver, Utah, USA. Small crystals of this gem were first found in 1905 in the Thomas Range in Juab County, Utah. The mine bearing gemstone-quality red-beryl was found in the 1950's. The biggest red beryl crystal ever found was 14mm by 34mm, weighing about 54 carats. The average faceted red beryl gemstone weighs about 0.15 carats. Red beryl has a hardness of 7 - 8
Red Diamond	Red diamonds are rare, fancy diamonds and are quite valuable. Diamonds are precious, lustrous gemstones made of highly-compressed carbon; they are one of the hardest materials known. Diamonds have a hardness of 10
Reeding	Decorative moulding composed of narrow parallel convex threadlike forms, usually confined to borders A form of ornament resembling that used on classical columns. Very popular for chair and table legs during the late 1700's. Reeding is the relief line on either side of a scooped out channel, these channels are called fluting, they run together in close parallels, divided by the 'reeding'.
Refraction	When light enters a medium with a different optical density,like a gemstone, the light is bent at an angle and also changes its speed $Refraction$ $Refraction$ $Refraction$
Refractive Index	The refractive index is a measure of how light is refracted in a substance like a gemstone. In doubly-refractive stones, the light is split into two light rays when it enters the stone, and the rays travel in different paths - so these stones have more than one refractive index
Refractometer	A refractometer is a device that measures the refractive index of a gemstone $Refractometer$
Regency	A term used to describe that period of furniture-making between about 1800 and 1840. In fact, the Regency began in 1811 and ended in 1820 with the death of George III, the Prince Regent succeeded him as George IV and was in turn succeeded by William IV in 1830
Repeater	A clock or watch where the user is able to pull a cord, depress a lever or press a button to get the clock to repeat the strike for the last hour, and often the last quarter hour (quarter repeating) without having to read the hands.