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Home > Publications > Historic New England Magazine > Winter/Spring 2005 > Caring for your Fine and Antique Jewelry

Caring for your Fine and Antique Jewelry

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ABOVE  Jewelry made of organic materials. Branch coral necklace, nineteenth century. Tortoiseshell arrow pin with pique gold stars, c.1860–1880. Gold and tiger claw brooch, part of a set acquired in Bombay, c.1875.

A few simple techniques of handling and care will help you maintain your personal collection of jewelry in good condition. The first thing to consider is storage, because proper methods can prevent damage from abrasion and tangling. Chain necklaces and bracelets should always be laid out so that there are no kinks or knots in them, as these can stress the fragile links and cause cracks or breaks. Jewelry boxes with compartments will keep fragile objects separate.

Alternatively, you can wrap your jewelry in clean acid-free tissue or store pieces individually in an all-cotton jewelry bag to prevent abrasion and minimize exposure to airborne pollutants. Clear polyethylene plastic bags or commercial jewelry bags made of Pacific Silvercloth or Corrosion Intercept, both of which contain corrosion inhibitors, are also recommended. Be wary of jewelry bags made of silk or wool, which contain sulfur, and of unidentified plastic, which may contain unstable plasticizers, as they can cause discoloration and deterioration of silver and copper alloy metals. Before putting jewelry away for long-term storage, it is important to remove salts, lotions, and grime to prevent them from attacking the metal surfaces. This can be done by gently wiping or brushing the items.

Stones and gems, which are actu-ally quite fragile, also benefit from proper handling and storage. Many gems can crack and chip when knocked or dropped. Diamonds are extremely hard, but sapphires, emeralds, and rubies can crack and shatter. Opals are very soft and often chip or become dull from abrasion. As they contain a fair amount of water, they are easily desiccated. For this reason, they should not be stored in dry, hot environments, nor should they be stored in water or oil, as some old household remedies recommend.

A few basic measures will also help keep your jewelry clean. Most metals other than iron can be cleaned with a clean cotton-tipped swab or a cloth lightly dampened with distilled water. For heavier grime, you may use mineral spirits. Always avoid soaking in water, especially tap water, or the use of chemical cleaners, ammoniated compounds, or acids. Many commercial cleaners contain harsh detergents and chelating agents (compounds that are useful in removing dirt but attack and pit metal surfaces), which can permanently alter and damage many metals. The use of alcohol or acetone to clean your jewelry is not advised, as many metals, especially copper alloys like brass or bronze, may have been lacquered or coated with a protective varnish, which will be removed or altered by the application of a solvent. Gold- and silver-plated items are of special concern when handling or cleaning, because their thin metal surfaces are easily abraded and removed. When polishing, take care to use non-abrasive cleaners in order not to damage the thin plated surface and expose the metal substrate beneath.

Pearls, coral, and shell objects are all forms of calcium derived from living organisms. They are particularly susceptible to damage from acids and ammoniated compounds and should never be cleaned with commercial cleaners, which may contain harsh chemical agents, nor should they ever be submerged in water or cleaned ultrasonically. Strings of pearls should be checked annually by a jeweler to ensure the stability of the string and knots. If you wear your pearls regularly, have them restrung every ten years or so.

Two other organic materials, ivory and bone, are also used in antique jewelry. Both are easily damaged by contact with acids and ammoniated compounds. They are also hygroscopic, meaning that they can swell in high humidity and shrink in dry conditions, which makes them very fragile. Ivory miniatures are especially delicate. They should be worn only on special occasions and stored in a cool, moderate and stable environment.

ABOVE LEFT  Cameo earrings matching the brooch on p. 7, mid-nineteenth century.
ABOVE RIGHT  Archival supplies such as acid-free tissue, Corrosion Intercept bags, Pacific Silvercloth, and cotton gloves
ABOVE  Bracelet, Italian micro-mosaic and goldstone, c. 1840. Recent gift of Mrs. George Carlson. Such jewelry was deemed fashionable for day wear.

Tortoiseshell, baleen, feathers and hair, in addition, are all organic materials found in antique jewelry. They are not only susceptible to the same damages mentioned above but are also vulnerable to attack by insects. Hair jewelry—rings, necklaces and pins—requires very gentle handling and proper storage in a clean, stable environment that is routinely checked for insect activity and mold.

Amber, a fossilized tree resin, and jet, a fossilized form of coal, can both be damaged by contact with solvents, such as acetone and ethanol. Because they may contain internal inclusions and fractures, they are also susceptible to cracking and cleaving. Cast iron was sometimes used to make imitation jet; such items can easily be detected with a magnet. Cast iron is susceptible to corrosion and should not be cleaned with water or stored in a humid environment. Instead, clean cast-iron objects gently, using mineral spirits.

Some modern materials, such as early rubbers, and plastics, like Cellu-loid, and Bakelite, were used to imitate more expensive materials like ivory, amber, and jet. These early formulations can be unstable, becoming discolored and brittle over time. Storing objects made of these materials at high temperature and humidity within a closed environment can accelerate their deterioration, releasing volatile gases. These, in turn, may attack some metals and organic objects stored nearby. Thus it is important to store items containing such materials separately in an environment that is cool, dark, dry, and well ventilated. Take care as well when cleaning plastic objects, because some solvents, like acetone and ethanol, or even water, can alter the surface and accelerate deterioration.

We recommend that you have your fine jewelry, especially delicate settings with prongs, checked periodically by a professional jeweler. Objects containing more unusual materials, such as tortoiseshell, ivory, and feathers, or hand-painted miniatures on ivory, should be treated by a professional conservator. In most cases, good storage and cleaning practices and careful handling will ensure that your jewelry will last to become cherished heirlooms.

—Julie A. Solz
Team Leader for Collections Services

 
 
 

Archival supplies such as acid-free tissue, Corrosion Intercept bags, Pacific Silvercloth, and cotton gloves, are available from...

University Products
1-800-628-1912
www.universityproducts.com

Gaylord Archival
1-800-448-6160
www.gaylord.com

Caring for your Fine and Antique Jewelry