The making of Jewellery

The making of fine jewellery requires both patience and skill.  It also needs a thorough understanding of precious metals and gemstones.  There are three separate crafts in fine jewellery making: mounting, setting and polishing.  These make the jewellery which has been designed by a trained designer, and for which the gems have been selected and prepared to fit the design brief.

The mounter is the skilled craftsperson who makes the framework of a piece of jewellery.  They handle metal, form it and drill and open out the holes so that the gems selected for the mount will fit perfectly.  There is no sparing of detail; every part must be perfect whether it shows or not.  The different sections must be soldered together without any visible joint - and a complex brooch or necklace may have dozens of parts.

The mounter also learns how to prepare materials to make the catches for brooches and clips for earrings.  Mounting is primarily handwork.  Mechanical aids often assist: saw frames, pliers, hammers and gas torches are used. The more exclusive craftspeople use small oxygen and gas torches essential when working with platinum.  In Birmingham some mounters prefer the mouth-controlled blowpipe. Used in conjunction with the Birmingham side light, the method dates back many centuries and leaves both hands free, whilst others use the hand-held torches of gas and pressurised air or butane varieties.

Some fine jewellery is now produced using batch-produced components either cast or stamped. These components must be carefully prepared, shaped and adapted to suit the stones and the designs of the particular piece of jewellery.  Much of the laborious routine is thereby removed enabling the craftsperson to apply their skill to the utmost advantage.

Trainees learn their skill first using base metals.  Once their skills develop they are allowed, under supervision, to make all the parts of a mount for the piece of jewellery in one of the precious metals – gold or platinum. 

The jewellery setter brings together the work of the gem sorter and the mounter, using many different tools with strange names e.g. spitstick, flat scorper or bullstick, with the added essentials of a keen eye and a steady hand.  They make the minute adjustments to the mount that ensures the stones fit and are held firmly.  They may have to cut away a merest fraction of metal so that the diamond or gemstone will fit exactly.  The stones are then fixed securely in the mount, held by grains, claws, or plain rubover.

There are many different kinds of setting used in jewellery, all adding to the interest and variety of the work.  For mounter and setter alike, every piece of jewellery is an individual piece of craftsmanship.  Its design may be similar to others, but each mount and the job of setting must be approached as a unique operation.  Fine large stones for instance, are usually claw-set, the small metal claws fitting securely over the girdle of the gem.  Smaller stones may be pave set, massed together like a cobbled street, but each individually and firmly placed in its setting.

The making of chains for bracelets and necklaces is a specialised branch of the trade.  Some chain is primarily hand-made, some is made by precision multiple action machines, but chain-makers are normally trained in both types of work. There are a number of skilled jobs in chain-making which includes wire drawing, coil winding, pattern making, linking, soldering, filing, machining and polishing.  Rolling and drawing metal in to wire is of course the basic work of a chain-maker who then winds it round spits or madrill.  When it is taken off, it looks like a coiled spring, a saw then cuts this, and each half coil is ready to form a single link, which is joined or jumped together and soldered.

 While many of the basic materials of the jeweller are nowadays prepared by specialist manufacturers - such as wedding ring tubes, ring mounts, bracelet tubes and even castings made from the jeweller’s own master patterns - many manufacturers still prefer to produce their own castings.  The investment casting process is one of the most popular and important in the quantity productions of jewellery.  The quality of the finished casting depends on the excellence of the master model from which the copies are eventually cast.  It requires a considerable amount of training, as does the study of advanced casting techniques.  Similarly, the preparation of the rubber mould is a skilled operation.  First of all the master pattern is made, perfect in every detail.  This is laid between sheets of rubber, which is then vulcanised by inserting into a press and using heat and pressure.  Cutting the now hard rubber is a job requiring great skill and dexterity.  It must be parted cleanly, using sharp scalpel-like tools, rather like those used by a surgeon.  Following the cutting process, the two halves of the mould must contain locating slots so that they fit perfectly together.  Pressure is then applied to hold the mould in the original position and wax is injected down the sprue hole.  When cool, the hardened wax is carefully removed.  Each wax model is carefully checked and kept clean, awaiting mounting onto a large wax sprue to form a tree.  A metal can is placed around the wax tree containing a number of wax models and these are coated with a refractory investment; this is usually crystobalite or quartz based.  When the process of investment is completed and the refractory material has dried, the cans are placed in an oven, which is gradually increased in heat, the wax that in non-residual is removed. The given name for this process is the ‘Lost Wax’ technique of casting.

Into the space left by the lost wax, molten metal is cast by the use of a machine known as a centrifuge.  The arm in the centrifuge revolves and throws the molten metal into the cavity.  The spinning continues until the metal solidifies, making sure that when the castings are cool, they will be free of any porosity giving dense castings.  After allowing for cooling, the castings are immersed in water to remove the plaster.  They are then cleaned, cut from the large sprue, when they may be filed and any excess material removed, and ready for the next process.

A new technique used today is to cast jewellery with the stones set in the wax so when the article is cast and comes out of the investment, it already has the stones set in it.

 The stamping press produces some jewellery parts.  The setting of the machines used is a highly skilled occupation and the process is very widely used in the manufacture of jewellery and allied products.

 This work includes soldering the various parts together, and as in chain making, the linking up of the chains for bracelets, necklaces and for link fastenings.  In some factories, assembly is becoming more and more mechanised, even to the extent of automatic soldering.  Most young people being trained to assemble jewellery will also find that they are being trained in the various finishing processes as well, so that they enjoy considerable variety in their work as well as making production more efficient and economical by being more rewarding to themselves and the company.

 Decorative processes used today range from the traditional handcrafts: chasing, engraving and more modern techniques of diamond milling.  Another important part of the trade today is plating, used both as a durable tarnish-free finish on silver and other noble metals to improve the appearance of the base metals used for costume jewellery.