Like in any industry, there are a lot of terms and definitions that an insider may be familiar with but can be mind-boggling for anyone else. Here at JAREEYA we started to put a glossary together for frequently used terms and definitions with the aim to clarify commonly used terms and phrases.

Due to the wide range of precious and semi-precious gemstones available, we plan to give them a separate list for easy access to the gems you are interested in.



A mixture of at least two different metals that are melted together to form a new metal with different properties to the individual metals used. It is not possible to separate the metals by mechanical means like disassembly but the article must be melted again. Most jewellery is made of alloys from the various precious metals to increase durability and optical characteristics.


Base metal

An inexpensive and non-precious metal such as copper, nickel or zinc.


An alloy made from copper and zinc


An alloy made from copper and tin


Cubic Zirconia

The cubic crystalline form of zirconium dioxide (ZrO2). Not to be confused with zircon (ZrSiO4), a zirconium silicate. The term "cubic zirconium" is sometimes erroneously used.



The hardest known natural substance which consists of carbon in its pure form. Thanks to its extreme hardness, durability and beautiful optical characteristics, it is a very popular gemstone in the jewellery industry.


Fine Gold

An item that is made of pure gold and has a fineness of 999 (24ct gold).


The amount of precious metal in relation to the other alloying elements. For example, 750 Gold consists of 750 parts gold and 250 parts other metals.


Gold Filled

Jewellery, that has a solid layer of gold mechanically bonded to sterling silver or a base metal. The amount of gold must constitute at least 5% of the item's total weight. If the weight of the gold is less than 5% of the item's total weight, then the related terms "rolled gold plate" or "gold overlay" may be used. The gold layer is around 5-10 times thicker than for regular gold-plated items and 15-25 times thicker than gold electroplated items.

Gold electroplating

Base metal is coated with a very thin layer of gold. The piece is put into a gold plating solution and by means of an electric current gold is coated onto the piece. By varying the duration and amount of current used, the thickness can be altered. A maximum thickness of 2 microns is allowed for the article to be called gold-plated. For very thin layers, the terms "gold flashed" or "gold washed" is sometimes used in the US.


Karat (Carat)

easurement of gold purity. One karat is 1/24 pure gold, meaning that 24ct is pure gold. Not to be confused with carat, the weight unit used for gemstones, equalling 0.2g.

Karat Gold

A gold alloy with a purity of at least 9ct (for the UK, the minimum gold content differs between countries).



The name given to naturally occurring silicon carbide. It is in many ways similar to diamond, exhibiting extreme hardness and optical qualities to that of diamond. For that reason, Moissanite is frequently used as a cheap alternative to diamonds and also used in scams where the sold "diamonds" are in fact Moissanites. Moissanite can be distinguished from diamond due to its higher electrical conductivity and birefringence.



A tin alloy. In England, it it is made of 91% tin, 7% antimony and 2% copper but elsewhere the alloying elements and percentates may differ. Other elements used for pewter include lead, bismuth and zinc.

Platinum Group Metals (PGM)

Platinum and the other five elements that have similar chemical and physical properties to it, namely palladium, iridium, osmium, rhodium and ruthenium.

Precious Metal

Gold, Silver and the Platinum Group Metals

Pure Gold

Same as Fine Gold. An item that has a fineness of 999 (24ct gold).


Rolled Gold

A layer of gold that has been mechanically bonded to the underlying metal. Rolled gold plate may be abbreviated simply as gold-plated and an other term used is gold overlay.



A gemstone variety of the mineral corundum. Sapphires are typically blue but fancy colours like yellow, orange, green and purple to exist.

Solid gold

A gold article that is not hollow or plated.

Sterling Silver

A silver alloy that consists of a minimum of 92.5% silver. The remaining 7.5% are made up of other metals, usually copper



A blue/violet variety of the mineral zoisite. It is a relatively cheap gemstone and often substituted for the more expensive sapphire. It is often heat-treated to achieve its famous deep-blue colour.



Sterling Silver Article that has a thin layer of gold (at least 2.5 micrometers thickness) electroplated or mechanically bonded onto it. The term is mainly used in the U.S. and is less common in the UK.