Terminology

Acid Test: A method of determining the fineness of gold by subjecting it to various acids. Nitric acid is used for testing gold up to 10K, but gold finer than 10k only reacts to a mixture of nitric acid and hydrochloric acid known as aqua regia. The test is very easy to perform by scratching the sample onto black stone and then applying the acid. If the sample disappears then it is not gold.

Electroplating: A process using electrical currents to coat objects with a thin layer of gold. The thickness depends upon the amount and duration of the current. I

Embossing: Embossing produces raised figures or patterns on flat or hollow articles. The use of punches and hammers on the back or inside of the article creates the design on the front.

Filigree: Ornamental open work executed in fine gold or silver wire, formed into flowers and arabesques. The general patterns are of a very delicate nature.

Fools Gold: Iron pyrite is often mistaken for gold and often found associated with it. Called "Fools Gold", it is hard and brittle, whereas gold is soft and malleable.

Gold Filled: An item made of a base metal is covered by a sheet of gold, at least 10k quality. The gold is bonded to the base metal by a mechanical process such as soldering or pressure rather than electroplating. The weight of the karat gold covering must be at least 1/20 of the total weight of the article. A mark such as 1/20 14k gold filled means the article was covered in 14k gold and the gold layer makes up 1/20 of the weight.

 

Malleability: Malleability is the property of some metals to be extended in all directions by hammering without cracking or breaking. Gold is the most malleable of all metals, it can be hammered to a thinness of 0.000005 of an inch.

Matte Finishing: Is a dull or frosted texture applied on a metal article by scratching the surface in one direction only.

Nugget: A natural gold nugget is water worn mass of placer gold (a form of natural gold). It has been washed from it's containing rock and deposited in a riverbed. Weights usually from 30 grams to 50 kilograms. Goldsmiths can recreate a similar look to the natural nugget by melting down gold to form an irregular shape. This is also called a nugget of gold.

Oxidization: Is the brassy discoloration of gold. Gold chain on the chain wall or gold rings left in the showcase may oxidize just from the air around them. Usually oxidization occurs wit ha chemical reaction to the alloys in the gold. Strong cleaners or perfumes may cause gold to discolor. In some cases on a ring the base of the head will discolor while worn because of a reaction with the solder and the chemical balance of the person wearing the ring. To remove oxidization from the product it usually must be polished and cleaned professionally.

Rhodium plate: The same process as electroplated (gold) except the color is a white finish.

Rolled Goldplate: The same as gThe same as gold filled, except that the weight of the karat gold is less than 1/20 of the weight of the total piece.