Differences Between Solid Gold, Gold Front & Back, Rolled Gold & Plate
What are the differences between solid gold, gold front & back, gold plated, gold filled, rolled gold, gold cased, vermeil and pinchbeck?
What do the terms ormolu, parcel-gilt, bronze dore, mercury gilding, fire gilding, gold wash & fool's gold mean?
This post will answer all of these questions.
Many people spend hundreds of £s on antique gold lockets, pendants and jewellery only to learn that they are not actually "solid gold".
Searching for gold jewellery can be a very time consuming and sometimes confusing pastime.
This post will help you to understand the differences between the terms and enable you to get the best collectibles which will retain their pleasing appearance without any need for cleaning or maintenance.
This term is often used to describe hallmarked gold. The benefits of purchasing items comprising from hallmarked gold are that you are given precise information and that they are valuable.
English assayed gold will be stamped with the carat of gold for example - 9c (375), 15c or 18c and often the maker's mark.
Fully hallmarked British gold will not only have the maker's mark, place of assay, the carat but also the date year. You can be certain that an item is Victorian, Edwardian or 1920s etc because of the date year hallmark. Nothing is left to chance. When perusing the assay offices' charts to ascertain the date of your item you should look at the font of the letter and also the cartouche that surrounds the letter, as the alphabet is repeated throughout time. Thankfully the assay offices use many different fonts to allow exact dating.
Solid gold will retain its glorious appearance without fading or any need for cleaning.
For the reasons stated above we prefer to source only hallmarked gold.
Gold front & back:
This term is often used to describe antique gold lockets which have a front and back made from gold. The gold front and back are applied to base metal or sometimes sterling silver. The main body of the locket, the case, hinge etc is base metal.
Many gold front & back lockets are sold for large sums of money and potential customers often assume that these pieces are the same quality and worth as solid gold lockets. This assumption is not correct.
This term means that the locket or piece of jewellery is plated with a layer of gold. Gold plating was invented in the 1840s. The process involves gold being deposited on base metal using electrical current. This method is not as durable as rolled gold or gold cased. The layer of gold is thinner. Do not be fooled by the stamp 14K H.G.E. Many people assume this is fourteen karat gold but the affix of the initials H.G.E. denotes that the jewellery is Heavy Gold Electroplate. The gold content in this instance is very low.
This method involves two layers of gold sheet being fused onto a sheet of base metal. Usually this process involves more gold than gold-cased or rolled gold items. Gold-filled is the term used when there is a heavier coating of gold than rolled gold. The plate of gold is soldered or welded on to metal. To qualify for the term gold-filled the item must have plating which is at least 1/20th of the weight of the metal that has been coated.
Rolled gold is achieved by mechanically plating or fusing a base metal sheet with a sheet of carat gold.
Some people describe rolled gold as gold-cased. The words are interchangeable as they are terms describing the same method which was invented in Birmingham c.1785. The process involves the soldering of a sheet of gold on to a sheet of brass. The ratio of the thickness of the two sheets would vary from 1:10 to 1:100. The double sheet was then rolled out to a thin sheet. The sheet is malleable and easily worked into ornate engravings. Sometimes the base sheet is silver. This is also called gold-cased.
Rolled gold or gold-cased are not the same as gold plate jewellery. Gold plating was invented in the 1840s and involves a process by which gold was deposited on a metal base using electric current. It is a less durable process than rolled gold or gold casing, with a thinner coating of gold.
In the mid -18th century the process of fire-gilding was developed in France. Later on it was discovered that jewellers involved in this work became blind due to their exposure to mercury, which was used in the process & subsequently it was banned. In modern times electrolysis is used to bond the gold. This method is safe. Vermeil jewellery / jewelry has been popular since the 19th century & it has gained great popularity, as it makes gold collectibles more affordable.
Often there is confusion about vermeil (ver-mey) & gold plated items. When a piece is said to be vermeil it can only have a sterling silver / high grade silver base. Gold plated items may have a base coat of metal, for example you can apply a layer of gold to base metals like, pewter, copper & brass. Often gold plated items have a very thin coat.
In order for an item to be correctly described as vermeil it must have a minimum millesimal fineness of silver .925 parts per 1000. The gold layer must be 14ct / k or higher in purity. The layer of gold must be at least 2.5 microns thick.
Whereas, gold plated items can be less than 0.5 microns thick. Vermeil & gold plating involves fusing gold onto another metal - in the case of vermeil this is sterling silver / high grade silver.
Vermeil pieces have a much higher value than gold plated items because of the sterling silver contained in the piece & also because vermeil is much more durable than gold plating.
Is a term used to describe a decorative technique which involves the application of a thin coat of gold to metal, wood, stone or porcelain. In China this practice was commonly used to enhance the beauty of bronze ornaments (gilt bronze) and porcelain. These items are described as gilt.
FRENCH ORMOLU AND CHAMPLEVE MANTEL CLOCK
BY JAPY FRERES PARIS LATE 19TH CENTURY
This is the word the western world uses to describe gilded bronze. The word is derived from the French moulu meaning ground pounded gold. Finely ground gold mercury amalgam was applied to the bronze. The finishing process involves placing the item in a kiln which leaves behind the gold coating, as the mercury evaporates in the form of an odourless gas once it is heated. The term bronze dore is used by the French to describe this technique. The English also describe items adorned in this fashion as gilt bronze. As you probably know mercury is an extremely toxic heavy metal. Inhalation of mercury can cause serious damage to the nervous, immune and digestive systems which can lead to fatalities. Few gilders survived into their fourth decade.
This practice was outlawed in France in c.1830, although it was not until the 1900s that these methods ceased to be used.
CHATEAU VERSAILLES GALERIE DES GLACES
© Myrabella / Wikimedia Commons
Ormolu is also known as mercury gilding and fire gilding. This process was superior to the other methods of gilding. Which is the reason why is was used to beautify the most cherished objects for over 2000 years. The final phase of this method was to burnish (polish) the gilded surfaces with a tool fitted with an agate head, known as agate burnisher. This gave the most superb finish to the gilding which is more durable than other methods. The French were considered to be the masters of fire gilding. The lavish lifestyles of the French royalty and nobility fueled this trade which had been perfected over the centuries until the Renaissance period by which time it had evolved into an art form in itself.
The alternative to mercury gilding was to use sheets of gold leaf which were then burnished, which bonded the gold leaf to the surface. The main reason why the dangerous method of mercury gilding was preferred to gold leaf was that the gold leaf was less durable. Mercury gilding coated the objet d'art with a thick gilded layer which was highly durable. The most prized items would be gilded multiple times building up a much thicker layers of gold. Whereas gold leaf is a thin layer more prone to wear.
GEORGE RICHARDS ELKINGTON 1801 - 1865
Oil on canvas by Samuel West
Eventually these processes were superseded by methods developed by Birmingham born Englishman, George Richards Elkington. When Elkington was fourteen years of age he was apprenticed to his uncle's silver plating firm. On the death of his uncle he was joined in partnership by his cousin, Henry Elkington. The Elkingtons had registered patents to protect their work applying electrical currents to metals. In 1840 John Wright, a surgeon based in Birmingham, discovered that a solution of cyanide of silver in potassium cyanide allowed for secure bonding of this precious metal to base metals.
The Elkingtons purchased and patented Wright's process and also the rights to Werner von Siemens improvements to the gold and silver plating process.
ELKINGTON & MASON AND COMPANY'S FACTORY
In 1842 the pen manufacturer, Josiah Mason, joined the firm. He was instrumental in focusing the business on manufacturing more affordable electroplated jewellery and cutlery. As a result silver plated wares became hugely popular in Victorian England.
By 1880 the company owned more than six factories and employed thousands of workers. The agreement between Elkington and Mason was dissolved on 31 December 1861.
After this time the company traded as Elkington and Co.
PARTIAL GILT TANG DYNASTY BOWL AD 618 - 907
Is also known as partial gilt, as the gilding does not cover the whole of the surface. This method of adornment enhances the contrast between the warm gilt surfaces and the cool silver.
In the Georgian era gold was 18 carat and completely out of the reach of most people.
It was not until 1854 that 9 carat gold was legalised.
Many people wanted to wear gold jewellery and early in the 18th century a London based clock maker and jeweller, Christopher Pinchbeck, invented Pinchbeck which looks like gold and yet is affordable to almost all people. Pinchbeck is an alloy of copper and zinc.
It is testament to the skill of Christopher Pinchbeck that the adorable mourning locket shown above still looks so glorious two hundred years after its creation.
Pinchbeck also became sought-after by travellers who dared not wear their gold jewellery whilst travelling in coaches along the highway. If highwaymen stopped their coaches they would hand over their Pinchbeck jewellery without suffering significant financially loses.
Some jewellery which has the appearance of gold is actually gold wash. This maybe hallmarked silver with a thin wash of gold. They may be base metal and the gold is easily rubbed away.
Some pyrite looks like gold. Unlike gold it is a mineral not a metal. It is an iron sulfide. Its shape is also different, it has a crystalline structure which has sharp edges and often appears to have a cuboid structure.
Unlike real gold which is malleable. Fool's gold will shatter when hit. Real gold will flatten or bend when pressure is applied. If you stick a pin into gold it will dent the surface, whereas pyrite will crumble when jabbed with a pointed object. Gold will not dissolve in acid but pyrite will.
Not all antique gold is hallmarked. Georgian and some Victorian gold may not be hallmarked.
However, there can be risks buying gold which does not have hallmarks.
The potential purchaser will read 'tests as gold' on the seller's advertisement.
Unfortunately items plated in gold will often 'test as gold' when an acid test is conducted.
The reliability of acid tests is widely disputed. This method of testing is invasive and can be destructive. As the name implies acid is used to test the jewellery to see if it is solid gold or gold plated.
The test involves removing a small part of the surface gold by making a scratch which is deep enough to see if base metal appears. The gold is tested by pouring on the acidic solution.
It is said that certain types of stainless steel can test as 18 carat gold!
We find it easier just to source hallmarked gold items.
Some jewellery professionals invest in high tech equipment (spectroscopy, elemental & isotope analysis) which will analyse non-precious and precious metals. These machines can cost thousands of £s but you can see the need for them, especially in the pawnbroking industry.
GOLDSMITHS' HALL PHOTOGRAPHED IN 1895
© The Goldsmiths' Company
The Goldsmiths' Company gained its Royal Charter in 1327. In 1300 King Edward I passed a statute requiring that gold and silver be of a defined standard. These precious metals were to be marked with a leopard’s head. This hallmark was said to have been taken from the royal arms. Hence it's name, the King’s mark. The Goldsmiths' Company was tasked with the job of supervising Britain’s first hallmarking system. This process has guarantee the fineness of precious metal in Great Britain since the fourteenth century.
The word hallmark derives it's name as the precious metals were marked in the Goldsmiths' Hall. Craftsmen were required to bring their goods to the Hall for assaying and marking.
Throughout history British gold has been assayed. The first British assay office was founded at Goldsmiths' Hall, London. Since then ten further assay offices were opened in Great Britain by Acts of Parliament granting them permission to make provision for the composition, assaying, marking and marks struck. The assay offices have the most advanced X-ray fluorescence machines.
London Assay Office