JEWELRY/METAL VOCABULARY

ACID SOLUTION - (sulfuric acid and water) – Used during the pickling process to clean metal of fire scale and flux. Sparex #2, a non-corrosive pickling solution, can be substituted for sulfuric acid. Also called “pickle”.

ACRYLIC – A synthetic, transparent, plastic compound used as a fixative

ALLOY – A metal composed of two or more metals. Brass is an alloy of copper and zinc, bronze is an alloy of copper and tin. Pure silver or gold, called fine silver or gold, is alloyed with base metals for hardness or other properties.

ANNEAL - To heat metal to a temperature below its melting point to relieve stress and make it soft and malleable, allowing for further working (1240 degrees Farenheit for sterling and copper)

BENCH BLOCK – Block made of steel used for forging, texturing or stamping.

BENCH PIN – Tool which clamps on to work surface to support small work for precise operations such as sawing, filing, sanding, forming, etc.

BEZEL – a strip of metal bent around the edge off a stone or other object to hold it in place.

BOBBING – a buffing compound coarser than tripoli, not as coarse as pumice.

CABOCHON – a stone with a smooth curved surface.

CASTING – (cire perdue) Replacing wax model with molten metal by gravity, centrifugal force, steam, etc. There are other methods using a matrix other than wax.

CHASING – working a sheet of metal from the front with hammer and punches to create a texture or low relief.

CHASING HAMMER – Broad, flat-faced hammer shaped with a long, thin-necked handle for rapid hammering; drives chasing tools and other punches.

CRATTEX – Name of a rubberized abrasive wheel used on the flex shaft or polishing machine.

CRUCIBLE – a vessel made of refractory material such as clay or porcelain, for melting metals when a high degree of heat is required.

DAPPING PUNCHES AND DIE – a graduated set of hemispherical punches and a matching die with a hemispherical depression used to make domes in sheet metal.

DAMASCENING – Inlaying metal with gold and silver.

DEBUBBLIZER – A commercially prepared liquid solution applied to wax model during casting to avoid the formation of bubbles.

DUCTILE – refers to those metals capable of being drawn into fine wire. One gram of fine silver can be drawn into a wire 3 miles long, and one ounce of fine gold drawn to a wire 35 miles long! ELECTRODEPOSITION – the depositing (plating) of electrically charged metals onto a desired surface of object (matrix). Electroforming.

ELECTRUM – Naturally occurring alloy in silver and gold.

EMERY PAPER, STICK, CLOTH, BOARD – Cloth or paper coated with an abrasive grit used to remove file marks or scratches. Comes in a variety of grits; the higher the number, the less grit, and the smoother the results on the metal.

ENGRAVING – The use of a chisel or burin to remove metal from the surface of a sheet, leaving a bright cut line.

ETCHING – Removing metal from the surface of a sheet with an acid solution. Nitric acid will work on copper or silver, ferric chloride will work on copper, but not silver. The parts covered with resist varnish will be left, and the parts not covered with resist will be etched lower than the surface.

FACET – Flat faced areas on a gem stone.

FERROUS METAL – Metals containing iron.

FINDINGS – Mechanical fastenings which hold jewelry in position while being worn.

FINE SILVER – Pure unalloyed silver; after gold, the most malleable and ductile of metals. Too soft for most jewelry purposes, it is used mainly for bezels and as a base for enamels.

FIRE SCALE – A copper oxide that forms on unprotected sterling silver during annealing or soldering. It can be prevented by fluxing and removed by pickling.

FLEXIBLE SHAFT OR FOREDOME MACHING – Rheostat controlled chuck hand piece to allow for small, precise sanding, drilling and polishing.

FLUX – A commercial preparation containing borax, available in paste and liquid form. It absorbs oxides during soldering and helps solder to flow by forming a protective film which keeps air away from the metal. It is also used as an aid in melting metal when casting.

FORGING – Changing shape or thickness of metal by striking with a hammer.

GAUGE – Refers to the thickness of wire and sheet metal. The number, the thinner the metal.

HALLMARK – The marking of a piece of jewelry or metalwork as to its maker, materials or date of manufacture by striking with an appropriate punch or stamp.

INGOT – A cast shape of metal from which sheet, rod or wire can be forged.

KARAT – A term used to measure alloyed gold. The standards are based upon pure gold which has 24 karats; 18K gold is 18 parts pure gold and 6 parts another metal. Alloy gold may also be 22K, 20K, 14K, 12K, and 10K. Alloys below 10K cannot legally be stamped with a Karat mark. Do not confuse with carat, which is the unit weight for gem stones.

KILN – A furnace or heated chamber lined with a refractory material, such as fire brick, in which high temperatures can be reached. IRON BINDING WIRE – Soft, annealed iron wire used in binding metals for soldering. Available in all standard wire gauges.

LIVER OF SULPHUR (potassium sulfide) Used during oxidation to color or patina metal. Gives a bluish- black finish or patina to silver and copper.

MALLEABLE – The quality in metal which enables it to be stretched without cracking or breaking. Gold, the most malleable of all metals, can be hammered into semi-transparent sheets less than 1/3,000,000 of an inch.

MANDREL – A metal tapered rod, usually circular, for forming rings, bracelets and bezels. Also the small rod onto which flex shaft tools are attached.

MILLIMETER – a unit of measurement. 25.4 mm = one inch.

MO KUME GANE – A Japanese word meaning wood grained pattern in metal.

PATINA – A chemical change which occurs on the surface as metals age. It may be artificially induced by using chemicals or heat.

PICKLE – A mild sulfuric acid solution used to remove flux and oxides from metal.

OXIDATION – Strictly speaking, the combination of oxygen with, generally, the copper in the surface of the metal to form black copper oxide. Commonly used to refer to the “tarnish” which forms on silver, usually the black compound of copper or silver and sulfur (a sulfide).

PITCH – An ideal base or support for metal in engraving, chasing, and repousse. Composed of pitch, plaster of Paris, and tallow, it is easy to apply and remove.

PITCH BOWL (block) – A semi-spherical metal bowl filled with pitch. Supports work for engraving, repousse and chasing.

PITCH BOWL PAD – A leather ring or rubber pad which enables the bowl to be held at any desired angle.

PLANISHING – Using a smooth hammer andp recise blows to even out a sheet of metal. Removing coarser work marks.

PUMICE – A cellular volcanic rock used in powdered form as a polishing agent.

PUNCH –A sharp pointed pick or awl. When hammered into metal, makes a dent or hole for piercing.

REPOUSSE – Modeling of sheet metal in relief from the back, using a hammer and punches.

RPM – Revolutions per minute.

ROUGE – Red iron oxide used in the final polishing of both metal and gemstones.

SOLDERING – Process of joining two or more pieces of metal by running molten metal (solder) between them so that when it solidifies a firm joint is made.

STAKE – tools of hardened steel on which metal is hammered into shape. STERLING – Silver which is 92.5 percent pure, the remaining portion being a base metal, normally copper.

TRIPOLI (buffing compound) – A fast-cutting abrasive for removing scratches from metal.

VISE – Useful for holding stakes or work being filed or sawed. Clamps to workbench.