Plating is the process of depositing a thin layer of one type of metal onto the surface of another. It is usually applied to jewellery to add visual appeal as well as added protection and durability.
Electroplating is a modern-day alchemy of sorts, where chemical reactions plate all kinds of metals to achieve the desired finish. There are various types of plating used to create jewellery – from different karats of yellow gold to 18k rose gold, black and white rhodium, palladium, silver and anti-tarnish.
Electroplating on jewellery is done for a number of reasons. Some forms of electroplating are both protective and decorative; metals such as gold and silver are plated to create attractive finishes as well as for affordability and durability.
Alloys can also be plated in a process whereby the electrolyte contains salts of all the metals that need to be present in the alloy. A jewellery item’s hallmark will always denote what its metal core is made of.
The electroplating process involves passing an electric current through a conductive solution called an electrolyte. The metal atoms that plate an object come from the electrolyte, so if you want to gold-plate a jewellery item, the electrolyte must be made from a solution of a gold salt.
Two terminals called electrodes then are dipped into the electrolyte and connected to a circuit with a power supply. When electricity flows through the circuit, the electrolyte splits up and some of the metal atoms it contains are deposited in a thin layer on top of one of the electrodes to become electroplated.
The longer the process continues, the greater the thickness of the coating. As the electroplating process continues it uses up the metal salts.
Electroplating is a 200 year old technique used to create Pandora Shine and Pandora Rose. The first instance of electroplating gold onto silver successfully took place in 1805.
A selection of Pandora jewellery is electroplated to create unique finishes, affordable designs and innovative metal blends. Pandora currently offers three types of plating: rhodium-plated sterling silver, Pandora Rose and Pandora Shine. On Pandora Shine jewellery, 18k gold plating covers sterling silver, bringing a rich golden glow to designs and extra protection against tarnishing. A 14k rose gold plated finish encases our Pandora Rose unique metal blend, protecting it from tarnishing, while also providing the designs with a beautiful pink-hued sheen. Used on some of our sterling silver designs, rhodium is a precious metal belonging to the platinum group of metals, notable for being extremely durable and resistant to tarnish. A layer of rhodium plating brings a shiny finish and a bright lustre to jewellery.
We use Pandora Rose jewellery as an example.
• The container is filled with a solution of the salt of the metal that will be coated, e.g. 14k rose gold.
• The jewellery item to be coated (the cathode) is connected to a negative charge and submerged in the electrolytic bath.
• Metal bars which are connected to a positive charge (the anodes) are also submerged in the electrolytic bath.
• When electric power is applied, electrolysis will happen. The bath releases the metal content, e.g. 14k rose gold, to the surface of the cathode (the jewellery item).
• The longer the process continues, the greater the thickness of the coating. As the electroplating process continues it uses up the metal salts.
Plating is done to protect or decorate jewellery. For Pandora Shine, we use the process of electroplating to enhance the jewellery with lovely golden tones and a smooth and attractive finish.