Articles and Videos by Chris Corti:
As many jewelry manufacturers and goldsmiths know from hard experience, cracking in jewelry can occur at any time during its manufacture. It can also occur much later, after the jewelry has been sold to the consumer or during repair. Cracking can also occur in the processing of the starting materials (the casting grain and mill products from which the jewelry is to be made), and may not be detected until several stages later in the manufacturing process.This article discusses these causes as they relate to cracking and the steps that can be taken to minimize their occurrence. The particular focus is on karat golds, but much is also applicable to silver and platinum jewelry.
Tarnishing is superficial corrosion of the carat gold surface and is evident by a usually dark discolouration – the tarnish film. Pure gold, of course, is not susceptible to tarnishing and this property is generally not greatly reduced by alloying to carat golds as long as the gold content is high enough.
In many countries, regulations govern the caratage of gold solders used to make jewellery and, with few exceptions, gold solder alloys should be of the same caratage as the jewellery. One problem with the production of solders is to ensure a good colour match with the jewellery being assembled.
When questions arise about manufacturing quality gold jewelry, manufacturers are eager to talk shop with their peers and industry experts. They want to know if they are using the right alloy for a specific application, casting at the appropriate times and temperatures, and annealing properly when work hardening a piece. Rarely, though, does the conversation turn to refining-an area of jewelry manufacturing that poses more questions than answers in many manufacturers’ minds. Refining is a practice that must be done precisely and methodically to ensure the full recovery of gold, as well as an end product that is free of impurities, which can lead to quality problems when the metal is reused in production.
Electroplating is a method to put a metal coating onto an object, in our case a piece of jewellery, by placing it in a solution containing the metal to be plated and passing an electrical current through the piece and the solution. It is possible to electroplate coatings of most pure metals and even some alloys. In this paper, we shall concentrate on the electroplating of gold and gold alloys and rhodium one of the platinum group of metals with a good white colour and tarnish resistance – for decorative applications. Electroplating is a comparatively quick and easy process to carry out and does not require major investment in costly equipment. It can be done successfully with very simple, basic equipment. Finished carat gold jewellery may be electroplated with gold for several reasons.
This soft back book is a practical guide intended for practising goldsmiths and is developed from a number of articles by the authors originally published in AJM magazine. It comprises articles and projects on making and repairing jewellery. Its aim is to show how one can save time and boost profits when making or repairing jewellery through good practice. It features over 200 colour photographs that illustrate the various steps and techniques..
Electroforming is an old, established technology and, in its original form, it was a bit cumbersome to use. However, as with other jewelry technologies, it has made great strides over the last decade and is now a much easier and quicker process. In this article, I shall focus on gold, but other precious metals can also be electroformed successfully.
With over 300 tonnes of gold used in electronics each year, end-of-life electronic equipment offers an important recycling potential for the secondary supply of gold. With gold concentrations reaching 300-350 g/t for mobile phone handsets and 200-250 g/t for computer circuit boards, this “urbanmine” is significantly richer than what is vailable in primary ores.
Jewellery design is generally considered solely from an artistic standpoint, and the jewellery is viewed as an expression of a designer’s artistic talent. How does technology fit into this scenario? Certainly design and technology are involved in making jewellery, but are they linked? What is the relationship between design and technology? In this presentation, I will try to explore this relationship in terms of jewellery manufacture, with some emphasis on technology’s ole in innovative design. I hope to show that technology is not irrelevant to creative design, and that each feeds off the other.