Lapidary is the craft of working, forming and finishing stone, mineral, gemstones, and other suitably durable materials into functional and/or decorative wearable items.
Silversmithing is the art of working with silver, usually sterling silver (92.5% silver), at room temperature with gentle and carefully placed taps of a hammer. While silversmiths specialize in, and principally work, silver, they also work with other metals such as gold, copper, steel, and brass. They make jewellery, silverware, armour, vases, and other artistic items.
Because silver is such a malleable metal, silversmiths have a large range of choices with how they prefer to work the metal. Historically, silversmiths are mostly referred to as goldsmiths, which was usually the same guild.
Faceting is the cutting and polishing of the surface of a gemstone into a distinctive, and specifically proportioned, pattern of flat panels, or "facets". This is done with the intention of increasing the stone's reflection of light and its brilliance. This process is completed using a faceting machine. Faceting began in the fourteenth century; with the earliest fashioning simply to polish natural crystal faces Faceting is almost exclusively applied to transparent gemstones because this type of cutting maximizes reflection and refraction, and therefore the gemstone's brilliance, scintillation, and fire.
If the gem is correctly cut, then light that passes into the gem will strike the back facets, be reflected twice, and then return to the eye, that is if it hits at an angle that is greater than the critical angle. If the gem is not cut properly, the light entering the gem will be refracted out the bottom of the gem, or it "leaks" out from the stone, i.e. when light lands within the critical angle. The larger the gem's refractive index the smaller the critical angle; the smaller the critical angle, the shallower the stone can be fashioned and still maintain brilliancy.
A cabochon is a gemstone which has been shaped and polished as opposed to facetted. The resulting form is usually a convex top with a flat bottom. Cutting "en cabochon" is usually applied to opaque gems, while facetting is usually applied to transparent stones. Hardness is also taken into account as softer gemstones with a hardness lower than 7 on the Mohs hardness scale are easily scratched, mainly by silicon dioxide in dust and grit. There are five basic styles of cabochon cuts: single, double, lentil, hollow, and reverse. The general outline, or shape as viewed from above, is circular, oval, rectangular, heart-shaped, or irregular.
The single cabochon has a convex or arched up top and flat base. The double cabochon has both a convex or arched top and bottom, with the top usually higher than the bottom. The lentil cabochon is a double cabochon with both the top and bottom curvature equal, rather thin and flat. The hollow cabochon has a convex top and flat bottom, but the dome is hollowed out and polished. This concave surface enables better light transmission in dark stones. The reverse cabochon, although rarely seen, has the convex top with a concave or depression in it and flat bottom.
Lost Wax Casting
Lost Wax Casting is sometimes called by the French name of 'cire perdue', is the process by which a metal (gold or silver) is cast into a form using a wax mould. It is an ancient practice, the process today varies but the steps which are usually used in casting small metal items in the modern times are generally quite standardised.
Cutting and Polishing Specimen Slabs
The art of cutting all items of hard stone into a slab or larger pieces and then polishing the main surface.
Precious Metal Clay (PMC)
This is a clay-like medium used to make jewellery, beads and small sculpture. It consists of very small particles of precious metals (such as silver, gold or platinum) mixed with an organic binder and water. Metal clay can be shaped just like any soft clay, by hand or using moulds. After drying, it is fired in a kiln, with a handheld gas torch, or on a gas stove. The binder burns away, leaving the pure, sintered metal. Shrinkage of between 8% and 30% occurs (depending on the product used), but this is exploited by artisans to produce very fine detail.
Silver precious metal clay results in objects containing .999 pure silver which is ideal for enamelling. Gold clay is much more expensive to use by itself, but can be used to make beautiful accents on silver objects.
Metal clay is sold in sealed packets to keep it moist and workable. It is also sold as a softer paste in a pre-filled syringe which can be used to produce extrude forms and as paper-like sheets, from which most of the moisture has been removed. Silver metal clay is also available in a dry powder form to which the user adds water to obtain any desired consistency.