Rhodium is a member of the platinum metals group; the other members include platinum, palladium, ruthenium, iridium, and osmium.

Rhodium was first isolated in 1803 by English chemist William Wollaston. Due to the distinctive red color of the dissolved rhodium compounds, Wollaston named the new metal Rhodium based on the Greek word rhodon meaning "rose".

The primary sources for rhodium are in Russia, South Africa, and Canada. The industrial extraction of rhodium is complicated by the fact that it occurs naturally with numerous other native ores. Mixed with other metals such as platinum, silver and nickel, the separation and refinement of rhodium ores are quite expensive. Only about 9-10 metric tons are produced annually worldwide. As of this writing, its trading range on the world spot metals market are quite volatile.

Among numerous other physical characteristics such as hardness, and high reflectivity, rhodium has an extraordinary resistance to most acids and corrosive substances. It is one of the few "white" metals that will remain bright and reflective under all atmospheric conditions at ordinary temperatures. As a result, electroplated surfaces that utilize rhodium plating remain scratch resistant, bright and attractive for years.

Rhodium was used as a novelty in the early 1920's to demonstrate its chrome-like brightness to prospective customers by the plating trade. Commercially, rhodium's presence grew quickly by the mid-1930's. Rhodium electroplated finishes on Art Deco style cigarette lighters, writing instruments and other fashion accessories became very popular. Some excellent examples of rhodium plated products were produced by the Ronson lighter company ("Fine Line"style circa.

Rhodium can be plated onto just about any metal surface. Primarily, our customers utilize rhodium to plate metals that are easily tarnished such as sterling silver, nickel, and copper alloys. back to the top

The plating thickness for decorative rhodium platings used by jewelry manufacturer can range from .05 microns to 1.5 microns. For most decorative applications, a thickness from .10 microns to .50 microns are utilized for maintaining long term "brightness". Industrial platings for specialized applications may utilize thicknesses up to 5.0 microns. However, rhodium finishes above 2.

Among the "white" decorative platings, rhodium is considered "best in class" in terms of toughness and wear resistance. Most items plated with at least .5 microns of rhodium are usually more scratch resistant than prior to being plated! Electroplated rhodium has a hardness ranging from 400-550 vickers which makes it very resistant to incidental abrasions.

Rhodium, a member of the platinum family, provides a hard, protective coating to white gold which brightens the color. While not used universally, it is an accepted practice in fine jewelry. This picture demonstrates the visual impact of Rhodium. The bottom ring is white gold without Rhodium, the top ring is white gold with a Rhodium coat. Some people find that the Rhodium plating degrades over time in daily wear, gradually revealing the color underneath.

Stainless Steel lasts longest, followed by Rhodium and then Gold. Gold tends to tarnish after time. Also, Gold is used to tonify (+), while Stainless Steel is neutral.

This refers to our silver colored finish. Instead of silver which tarnishes easily we use Rhodium. Rhodium is a very durable engravable metal which will not tarnish. Part of the platinum family it is very expensive and is considered a very high quality finish.

No, as a rule the electroplating process does not hide surface imperfections. In fact, due to the diffusive reflection of incidental light rays, pre-existing cosmetic imperfections are even more noticeable on a brightly plated surface! For best results the item should be polished to the desired level of brightness prior to rhodium plating.

One of the minor cosmetic trade-offs for plating rhodium onto silver is that the rhodium finish will not be as bright or reflective as the original silver finish. Rhodium reflects about 72%-80% of the light rays that strike it. Silver reflects up to 95% of all incidental light that strikes it. However, over the long term rhodium will stay "brighter" than silver because of its superior resistance to tarnishing and scratching.

With the exception of nickel and silver, any object plated with less than .10 microns of rhodium will eventually discolor due to the corrosive oxides that are "rising" through the microscopic pores within the rhodium's surface. This type of surface tarnish will eventually appear "yellowish' bright to the observer and is commonly found on decorative items such as jewelry chains and bracelets. Constant contact with skin oils and chemicals help accelerate surface discoloring.

Our most popular items plated with Rhodium are products made of sterling silver. Silver chains, bracelets, cuff links and holloware being the most frequently plated items. We are also plating stainless steel watch cases and men's accessories with rhodium to replace their original chrome finishes.

Yes, as long as the surface of the base metal (i.e.silver) is free of contaminants, rhodium can be successfully plated over just about any surface treatment.

Sterling silver items that are electroplated with a rhodium finish must still be designated as "Sterling silver" or one of its equivalent legal markings. For more detail on this topic visit the www.ftc.gov web site for specific guidelines. This article copyright 2003 by Metal Arts Specialties. All rights reserved. This material may not be duplicated or copied without expressed written permission. Thank-you

Until August of 2003 we offered silver jewelry as either "Natural" or "Rhodium" finished. A natural finish is simply a high polish which brings out the natural luster of fine silver (.925). All regular natural silver jewelry requires routine maintenance to remove tarnish and restore the finish. Rhodium plating is a complex and labor intensive process to effectively enhance the luster and prolong the beauty of silver or white gold. Rhodium is one of the platinum family metals.