Patina is the look of metal that has gently aged through exposure to oxidation, the effect of weather and time. It is considered a mark of maturity and authenticity. Antiques are often valued and judged by their patina. Several techniques are available to restore, care for or enhance patina on gold and other metals. Some of the techniques involve the use of highly toxic chemicals that require extreme care. Other techniques produce patina results from commercially made finishes.
Immerse the gold item in impure potassium sulphide salts, also known as "liver of sulphur." Other liquid sulphides and polysulphides are also used in a diluted form, allowing a patina film to build up slowly, densely and, typically, permanently. It is typically available in dry rock form that is broken down and dissolved in hot water.
Submerge hot gold in ammonium hydroxide, also know as "aqua ammonia," a clear colorless liquid with a powerful, suffocating smell used in many household cleaners. The solution works most effectively at room temperature, producing a black patina appearance.
Immerse the gold item in a solution made from barium sulfide to create a bluish-black patina coloration.
Submerge gold alloy in boron powder and treat with heat. This new treatment, known as a Boronizing treatment, produces layers of marked colors, such as blue, purple, gray and yellow-brown.
Use a commercially prepared patina, available through home improvement, hobby and craft supply stores, to refine the patina appearance. Follow the manufacturer's package instructions.
Let nature take its course through oxidation, which is a chemical reaction between the metal and oxygen that happens over time through being exposed to weather and the outside elements. It is the most natural process but typically takes many years.
Wipe the item regularly with a soft, dry cloth. Do not use harsh detergents, cleansers or solvents on your gold item.
Tips & Warnings
- Pure gold does not respond to boronizing treatment. It must be gold alloys, which are combinations of pure gold and other metals.
- Take precautions when using any chemical that is toxic. Thoroughly read the manufacturer's chemical safety information and instructions on the package. Do not taste or sniff chemicals. Wear protective clothing, rubber gloves and protective glasses. Use chemicals in a well ventilated area only.
- Keep chemicals away from your eyes and wear protective splash goggles made from thick plastic and held on the head by an adjustable strap. Chemicals can effect eyes. Itching and stinging to burning and blindness can occur.
- Don't smoke, drink or eat while using chemicals. Do not store used chemicals near heat or flames.
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