Pancyprian TS Jewellery III key terms

The proportion of pure precious metal in an alloy, expressed in parts per thousand (e.g. 750 means 750/1000 gold). It determines legal hallmarking and the metal's working behaviour.

A metal mixture made by melting a precious metal with other elements to change colour, hardness, workability or melting point. Sterling silver and 18K gold are common jewellery alloys.

An official stamped mark applied by an assay office confirming the metal type and its fineness. It also often includes the maker's mark and a date letter.

The registered stamp identifying the workshop or individual who made the piece. It allows the item to be traced to its producer and usually accompanies the assay office hallmark.

Heating metal to a specific temperature and cooling it to relieve internal stress and restore softness after working. It makes the metal easier to bend, file and shape without cracking.

The increase in hardness and loss of ductility that occurs when a metal is bent, hammered or rolled. It must be reversed by annealing before further shaping.

Rapid cooling of hot metal by plunging it into water or other liquid. In silver and gold it is used after annealing; in steel it produces hardness.

The ability of a metal to be drawn or stretched into wire without breaking. High ductility is desirable when pulling wire or bending thin sections.

The ability of a metal to be hammered or rolled into thin sheet without cracking. It differs from ductility, which concerns stretching rather than flattening.

Joining metal parts with a filler alloy that melts at a lower temperature than the parent metal. The joint is heated until the solder flows by capillary action into the gap.

A paste or liquid applied to a joint to prevent oxidation during heating and to help molten solder flow. It must be removed after soldering to avoid corrosion and staining.

A dilute acid bath used to remove oxidation, flux residue and fire stain from metal after soldering or annealing. The piece is rinsed thoroughly afterwards.

A dark surface discolouration on silver caused by copper oxides forming during heating. It is removed by pickling, often followed by polishing or depletion gilding.

The temperature at which a solder becomes fully liquid and flows into a joint. Successive solders in one piece must be chosen in descending order of this temperature.

A solder alloy of a composition that melts at a single, lowest possible temperature with no pasty range. It gives predictable, clean flow in delicate assemblies.

A fine-toothed saw with a spring-steel frame and thin blades used to cut curves and internal shapes in metal sheet. Blade tension and correct tooth direction are essential.

The orientation of the saw teeth, which should point toward the handle and cut on the downward stroke. Correct direction prevents the blade from jumping and improves control.

A small wedge-shaped wooden support clamped to the bench and used behind the saw frame when cutting. It supports the work and allows fine control near the cut line.

Filing by pushing and pulling the file sideways along the work while it is held across the file face. It produces a flatter surface and removes cross-file scratches.

The coarseness of a file's teeth, ranging from coarse bastard to fine smooth. Coarse cuts remove metal quickly; smooth cuts refine surfaces before polishing.

A measuring instrument with a sliding jaw and a vernier scale that reads to fractions of a millimetre. It measures outside, inside and depth dimensions of jewellery components.

A precision measuring tool with a calibrated screw that measures small thicknesses and wire diameters to hundredths of a millimetre. It is more accurate than a vernier caliper for fine work.

The permitted variation in a dimension or fit between mating parts. Tight tolerances are needed for settings and clasps; loose tolerances suit hand-finished decorative work.

A tapered steel or wooden form on which ring shanks are shaped, sized and hammered. Marked graduations allow the shank to be brought to the required finger size.

A graduated tapered rod used to measure finger size or check the internal diameter of a finished ring. Sizes are read at the point where the ring sits snugly.

A polished hardened steel or agate tool rubbed over metal to compress the surface and produce a bright, reflective finish. It also tightens settings without cutting metal.

A finishing process using a rotating cloth mop charged with abrasive compound to remove fine scratches and produce a mirror surface. Different mops and compounds follow a graded sequence.

A setting in which a strip of metal is raised around the stone's girdle and pushed over it to hold it securely. It protects the edges of the stone and suits cabochons.

A polished steel or brass tool with a curved edge used to push the metal wall of a bezel over a stone. It moves metal gradually without scratching the gemstone.

A setting that holds a stone with several raised metal claws bent over the crown edge. It exposes more of the stone but leaves the girdle more vulnerable to knocks.

The widest edge or rim of a cut gemstone, separating the crown above from the pavilion below. It is the part usually gripped by prongs or enclosed by a bezel.

A gemstone cut with a smooth, domed top and no facets, usually with a flat base. It is commonly set in bezels and is typical for opaque or chatoyant stones.

The functional components added to a piece, such as clasps, jump rings, ear posts, bails and catches. Their strength and finish must match the rest of the article.

A small wire ring used to connect components such as a chain to a clasp. It should be soldered closed where security matters, and opened by twisting rather than pulling apart.

A fastening device that opens and closes a necklace or bracelet, such as a lobster, bolt ring or box clasp. It must be secure, easy to operate and proportionate to the piece.

A deliberate or natural surface colour change on metal, such as oxidised darkening in recesses. It is used for contrast and must be stabilised so it does not rub off.

Safety items worn in the workshop, including eye protection, dust masks, gloves and aprons. Correct use reduces injury from flying metal, chemicals, heat and dust.

A fan and duct system that captures dust and fumes at the point of generation, such as at a polishing mop or soldering bench. It protects the lungs from fine particles and metal vapour.