Your Jewelry’s Finish
September 26, 2008 § 4 Comments
Your jewelry’s finish is probably not something you’ve spent time thinking about, though it was likely a factor in choosing the piece you did. And the more you know about the finish on your jewelry, the better you will be able to care for it.
There are several common forms of metal finishing: polishing, buffing and burnishing. Among these mechanical finishes, there are similarities. They are applied by physical abrasion of the metal surface using a secondary media. The media may include cloth, stone, metal and plastics combined with finishing compounds to aid the process. Methods of application include wheel abrasion, hand abrasion, blasting, tumbling barrels and vibratory finishers.
Mechanical finishes can be categorized by the way the parts to be finished are handled:
- Individually handled and finished using wheel abrasion or hand abrasion
- Mass finishing using tumbling barrels or vibratory finishers
The highest quality mechanical metal finishes are usually obtained by individually handling the parts and using some type of wheel abrasion. Fine hardware, furniture, and motorcycle parts are typically finished using this method. These finishes include:
- Grinding – Used to remove large amounts of metal, grinding can be used to remove large burrs (deburring), heavy scale, rust, and major metal imperfections. The resulting finish has significant grit lines and needs additional mechanical finishing prior to electroplating.
- Polishing – Very often mistaken as a mirror bright finish, polishing is similar to grinding but uses finer grits and compounds to remove significant metal imperfections and small metal burrs. It is usually used prior to buffing in order to obtain a mirror bright finish. In some cases multiple polishing steps using progressively finer grits are needed to obtain the desired finish.
- Buffing – Using cloth wheels combined with compounds, buffing is a final mechanical finish that results in a mirror bright to near mirror bright finish, depending upon the base metal and/or prior mechanical finishing steps. Buffing does not remove a large amount of metal.
- Satin – Also a final mechanical finish, a satin finish is an even, fine-grain, brush-type finish. A fine grit polishing finish produces a finish similar to a satin, which can be achieved using emery paper 350 grit.
Mass mechanical finishing is usually referred to as burnishing. It is a cost effective way to remove burrs and brighten metal where a perfect mirror finish is not required. A wide variety of methods exist using different types of machinery, media, and compounds depending upon the base metal and the desired results. Burnishing is also often used for brightening parts after the plating process.
Cleaning your jewelry can affect the finish on the metal. This is particularly true if you have jewelry that is plated (this includes vermeil). Ask your jeweler how to best take care of your jewelry. Metals and gemstones each have special care requirements. Know these before you clean and you’ll be more likely to keep your jewelry looking good for years to come.