We get a lot of questions about precious metal surface finishes. How are they applied? Why? Finishes can be broken down into four main categories: Plating, Anti-tarnish treatments, Tool texture effects, and Patinas. Below, we will describe each of the finishes you can find on our jewelry supplies.
The plating process involves submerging metal items in a solution bath and using an electric current to deposit dissolved metal ions on the surface. It requires special skills, equipment and chemicals. Plating is the final step when manufacturing a finished jewelry product. Many manufacturers send out products to a specialized plating facility instead of doing it in-house. Not all jewelry pieces and findings are plated but it is becoming more common.
There are two reasons to plate an item. First, plating can alter the appearance of a metal. Gold plating is often applied over less expensive metals to give the look of solid gold at a lower price. Ruthenium is now a popular plating finish because of its striking black color. Second, plating is often used as part of finishing to give items a brilliant, evenly colored surface. Some items are easier to plate than to finish with other methods. Plating is especially common on jewelry chain, for example.
In the jewelry industry you should properly describe items by the primary material in the piece and then include details on plating. You should never call a gold-plated silver item “gold” because it would be misleading. It can be properly described as silver with gold plating or gold-plated silver. Similarly, silver items with ruthenium or rhodium plating should still be called “silver” along with a disclosure about the surface finishes.
Ruthenium – With its flat black, gun-metal shine, ruthenium is a striking contrast next to polished metals. This makes it a perfect material in mixed metal jewelry. It is highly resistant to wear. Because ruthenium itself is hard and brittle, the plating process is slower and therefore more expensive. It’s part of the platinum group of metals (Ru).
Gold – Gold plating over brass or sterling silver is a very common practice in jewelry. It consists of a thin layer of solid gold (less than a fraction of a percent) that is electroplated onto the base metal. As the gold layer wears out over time, tarnishing will begin to show on the piece where the base metal is exposed. Vermeil is a heavy layer of plating. Gold plating is often applied over gold-filled as well. The plating step adds a higher polish to the metal and evens coloration that can vary in raw gold-filled material. However, it is important to emphasize that gold-filled material is not plated even though plating may be applied as a finishing technique. You can learn more about it in our gold-filled material articles.
Rhodium – Very pricey but the result is a beautiful, steely look to the metal. Rhodium is more gray than silver. The thickness on rhodium plating varies greatly by manufacturer, but the thicker the rhodium, the more tarnish resistant it is. It’s the perfect plating for diamond jewelry because it reflects the sparkly diamonds and makes it difficult to distinguish where the stone ends and the metal begins. It is frequently used in pearl jewelry to delay tarnishing because it is so difficult to clean metals alongside fragile pearls. It’s part of the platinum group of metals (Rh). Note: properly rhodium plated sterling items use a nickel barrier layer between the silver and the rhodium to prevent ion migration across the layers. People with nickel allergies should generally avoid rhodium plated items.
Fine Silver – Many people wonder why you would plate a sterling item with more silver. Good question! Fine silver plating over sterling brightens up a silver piece and is more resistant to tarnishing compared to sterling silver because of the higher content of silver on the surface. It is the copper in sterling alloys that oxidizes the metal most rapidly. Plating with fine silver is often more effective and efficient than surface finishing with tumblers, abrasives and ultrasonics.
It’s important to note that any surface plating will wear off over extended periods of time depending on wear and environmental conditions.
Anti-Tarnish Treatment Variations
Some surface finishes are added to delay the onset of oxidation or tarnish on silver alloys. It is impossible to prevent tarnish on silver forever, but, you can increase the time it takes for oxidation to begin. The efficacy of anti-tarnish treatments will depend on many environmental factors so you cannot pinpoint a lifespan with any precision.
It is especially important to know about treatments if you plan to apply patinas to a piece. Any anti-tarnish treatment will prevent even patination on a metal item. Results will be splotchy and unpredictable. If you wish to oxidize your jewelry findings, it is best to select items without anti-tarnish. At Halstead, you will find that all of our items contain disclosure on anti-tarnish treatments in the item detail information online.
- Spray – Spray application of a chemical coating. Adheres quickly, coats surface.
- E-coating – Electric current bonds an extremely thin plastic film to surface, lasts longer than spray. Acetone will strip away e-coating but you risk damaging the metal underneath.
Note: We do not recommend removing anti-tarnish treatments. Results will vary.
Tool Texture Effects
Tools and equipment can be used to finish metals or apply textures for visual effect. Many common practices are described below.
Sparkle – sharp, angled strikes with machined hammer heads. The sparkle solution is an innovative development to create the look of diamond cutting without actually piercing the surface and removing material. This maintains the integrity of the primary metal and is especially useful for a layered material like gold-filled.
Patinas are surface effects that change the color of a metal through a chemical reaction. The most common patina in silver jewelry is oxidation with liver of sulfur. This treatment accelerates and intensifies tarnishing to create a dark, nearly black surface. Patinas are usually applied to an entire piece and then the surface may be polished and finished to leave the dark color in relief only. This technique is commonly called antique finishing because it makes the metal look older or more rustic.
Note: patinas can be stripped away with abrasives or chemical cleaning.
For more information and examples of surface finishes for metal, take a tour of our website at www.HalsteadBead.com and take a closer look at your favorite findings, chains and other jewelry supplies. Visit our Pinterest boards for beautiful ideas and inspiration.