Jewelry Lovers

Spacers

Shell jewelry often looks better when the shells are separated by spacers, which can be turned ivory, wooden beads, nuts or seeds, or mother-of-pearl.

Pieces of mother-of-pearl (see below) can be turned on a lathe or made by cutting oblongs of pearl shell 2.5cm (lin) long by 6mm (tin) wide.

Make up two square wooden boards, about 30cm by 30cm (12in by 12in) and fix a handle to one of them. Cover one side of each board with wood glue and stick down very coarse sandpaper. Now place the oblongs of mother-of-pearl on top of the sanded side of the bottom board, cover it with the board with the handle attached, and rub the two boards together. It helps if all the oblongs are pointing in the same direction and if you rub the boards at right angles to the long axis of the oblong. Gradually the oblongs will lose their sharp edges and become cylindrical. If some oblongs are hard to smooth, round their edges with a sharp steel file, then sand with medium and fine sandpaper.

Drill through the finished oblongs (which are called ‘bangles’) along their axis. Drill from both ends and let the holes meet in the middle.

Square pieces of mother-of-pearl can be converted into round spacers by moving the two boards in a circular direction as you rub.

Stripping and polishing shells

Many shells have a shiny interior coating of nacre, which is better known as mother-of-pearl. This substance is composed of the same silvery, shimmering material as pearls, but whereas pearls are very rare and therefore precious, mother-of-pearl can be obtained in large quantities and is one of the cheapest of all jewelry materials. Stripping can be done in various ways. Small shells are simply left to steep in a solution of household bleach and water, in a proportion of one part bleach to four parts water, until the acid in the bleach eats away the blue-black outside layer of the shell and reveals the silvery underside of the mother-of-pearl. It takes a day or two for the outside coat (periostracum) to disappear. Leave the -shells in the solution in a glass jar and inspect them from time to time to seehow the stripping is progressing.

Once the periostracum has been removed, the shells should be well washed, first in a little liquid soap and water, then in clear water, toremove all traces of bleach.

Grinding will remove the periostracum of thicker shells. If an old- fashioned grindstone is available, you can force the shell against its edge while someone else turns the grinder, but a quicker way is to use a small grindstone attachment in the chuck [shell] of an electricdrill.

First cement the shell to a bench, using dop cement (lapidary cement). Melt the cement over a wax taper or candle until it is fluid, then dab the bench and the bottom of the shell with it. Stick the shell to the bench while the cement is still sticky. When the cement has cooled, the shell should stick firmly to the bench.

Work the grindstone in the drill slowly over the surface of the shell. Avoid cutting too deeply or making score marks. When you have ground away as much as you can with the grindstone, fit an abrasive head into a flexible drive and grind into all the small crevices.

Lever the shell off the bench with a screwdriver. When you have ground one part, stick it down in another position, then grind again. When the whole outside layer has been removed and the nacre is shining over the whole surface of the shell, stripping is complete and the shell can be polished.

Some shells, such as top shells and nautili, have such thin layers of periostracum that it is inadvisable to strip them mechanically, but they can be stripped with an alabaster knife, as used by sculptors and obtainable from sculptor’s tool merchants. This looks like a miniature scimitar, except that its curved blade has a sharp edge on both sides. Sharpen both edges well with a whetstone and cradle the shell firmly between the knees with enough pressure to hold it without breaking it.

Hold the knife by the point with the left hand and the handle with the right and scrape delicately at the outside covering, using the inside of the knife blade to fit snugly around the curve of the shell. Other sharp craft knives with disposable blades can also be used, and a razor blade in a safety holder will strip any awkward patches. Shells can also be rubbed down, first with a coarse, then with medium and fine sandpaper, and then polished.

Splitting shells

Shells can be split down the middle to show all the little chambers inside. This is usually done by professional shell craftsmen who use a lapidary wheel, but there is no reason why this should not be attempted at home.

Choose a fairly small shell. Cement one side to a board with dop cement. Clamp the board in a vice.

Make a cut along the top of the shell with a triangular-shaped file to start the saw cut. With a 2.5cm (lin) wide metal piercing blade in a hack saw, cut very gently through the nautilus, lubricating the blade with water as you go.

Instead of cutting straight through the shell make a pencil line first and cut along the line from two directions so that the cuts meet.

Lay the two halves on a sheet of fine sandpaper and rub them gently on it until the cut edges are smooth.

Polishing

A stripped shell has to be polished after stripping to bring out its beauty to the full. Rub first with finest flour sandpaper (usually `0′). Then rub it with a wet cotton rag dipped in powdered pumice.

Keep rubbing until a shine begins to show. Wipe off every trace of the polishing powder, dip another rag in the powder and polish afresh.

Finally rub the shell with a wet rag dipped in a tablespoon of copper sulphate dissolved in a cupful of warm water.

A coat of clear lacquer or embedding the shells in clear cast plastic resin will preserve iridescence.

Painting and dyeing

Shells can be painted with enamel paint sold for military miniatures. Before painting, clean the shell with a rag dipped in turpentine, then paint, preferably not over the entire surface but with a design which will allow the beautiful designs on the shell background to show through.

Gilt can be applied by painting a design on a shell with Japan gold size (tinted to show up against a white shell). Press gold leaf onto the size while it is still tacky [sticky], allowing it to dry hard, then gently brush off the residue of leaf with a stiff brush before burnishing smooth with a stone such as blood stone.

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