Metals 101, Plating vs Fill and other useful information
In the couple years I have been working with metal, I have come to the conclusion that the jewelry industry has done a great disservice to its customers. With the vast resources on the internet, shows, stores and so on I find that many customers are weary about metals on their skin for lack of information or just plain incorrect information given to them. This is for two reasons: cheap jewelry with harsh metal combinations (aka. metal alloy), and poor information/education spread by those in the industry. I still hear about the fact that cheap faux jewelry still circulates (often from other countries outside of the US) that contains toxic levels of heavy metals, plus the use of nickel in anything jewelry related which also causes harsh reactions in most if not all people.
The metals I use are as follows:
- Silver Filled Silver (10% Fine Silver)
- 99.9% Pure Copper
- Jeweler's Brass: CDA #230 alloy (85% copper/15% zinc)
- Sterling Silver
All my metal is purchased from American companies: Rio Grande & ParaWire
So let's talk about what all that means.
Silver Filled Wire
Everyone has heard of plated wire, it's known for poor quality and obvious flaking in dirt cheap jewelry or tricky expensive jewelry. You may have heard of "Sterling Silver Plated" or have had silver plated jewelry that loses it's silver a week in. The "plating" is done via electroplating, in simple terms it's the process of plating a solid object in a dilution of the metal ions you want to plate with. So for instance, gold ions on brass (if you're lucky it's the same color as gold).
(source: https://www.riogrande.com/knowledge-hub/gold-filled-vs-gold-plated-jewelry-explained/)
On the other hand, Silver Filled Silver or plainly Silver Filled or Gold Filled has a layer of fine metal 100x (or more) thicker than plating. The fine metal (Fine Silver 99.9% or 12 or 14 karat Gold) is formed into a tube and a like-color metal core is inserted, this would likely be brass for gold, and silver anodized (colored) copper for Silver. Both metals are permanently bonded together, and last for a long long time as they won't flake or be rubbed off like plating.(1)
A thing to remember with both plating and fill, is that metals can vary by the company that manufactures and/or sells them to crafts people or other companies. It's important to verify the manufacturer's country of origin and find trusted sellers to avoid toxic metals. Rio Grande is a trusted American Company, long established as the premier seller of quality metals to every level of jeweler and artisan. ParaWire is less known but they are a craft wire company and a part of Paramount Industrial Wire Company, a 100 year old American metal company that manufactures wire for industrial/construction purposes. Other companies may make plate or fill metal, but they can make a toxic core, like filled silver on nickel or gold fill on chromium or even lead. Nickel is an especially cheap metal in comparison to Brass alloys and Copper, and unfortunately companies out to make extra pennies may cut those types of corners.
"Base Metals" Copper & Brass
The other two metals I work with are 99.9% Copper and Jeweler's Bronze (CDA #230). I buy both Copper and Jeweler's Bronze from ParaWire and Rio Grande depending on the shape and amount I'm looking for. Rio Grande sells 1lb spools or custom cuts of metal which usually lasts me 4-6 months. ParaWire sells spools in smaller amounts, and with different specialties like tarnish resistance or anodized (colored) metals. The 99.9% Copper is straight forward, it's a pure metal with 0.1% possible impurities, I imagine that the environment where the Copper is formed is not a sterile "clean room" so the company has to account for dust and other particulates that may be unavoidable in the process. Jeweler's Bronze is an interesting identifier, Jeweler's Bronze is in fact a Brass Metal. CDA #230 Brass is an alloy of 80% Copper and 20% Zinc, the CDA indicates that it was annealed through bein cold drawn, the full acronym standing for Cold Drawn Anneal (vs HRA or Hot Rolled Anneal), not really important for the metal content but effects hard and softness of metal.
Sterling Silver
Sterling Silver is likely something everyone is familiar with, 925 Sterling Silver is an alloy - that is it's made with a percentage of other metals but requires a content of 92.5% Fine Silver. The other metal it is mixed with can be anything, depending on the manufacturer's country of origin and business practices. It could be 7.5% Nickel, or Copper, or Zinc; or even lead if the offending country has lose government regulation. I buy all my Sterling from Rio Grande, their country of origin is the United States. The US has many restrictions on heavy metals that are often toxic, especially to children under 12. These metals are: Chromium, Lead, Nickel, Arsenic, and Mercury.(2) While heavy metals aren't banned outright in the US, it restricts content to safe levels for each heavy metal and it's corresponding item type (ie. Kids Toys, Jewelry, etc). One reason your ears may react to Sterling Silver is that it could have a Nickel content of 7.5%; possibly safe enough to wear but not enough to be non-bio reactive to skin when touching it for long periods of time. In Rio Grand's Sterling Silver, Fine Silver is bonded to Copper as noted in their Safety Data Sheet for every type of Sterling Silver Wire.(3) Even though copper has a low bioreactivity, some people may still react to sterling silver ear hooks/earrings which is why there are other options available for sensitive skin which I will hopefully cover at a later date!
Sources
(1) Gold Filled vs Gold Plated Jewelry Explained: https://www.riogrande.com/knowledge-hub/gold-filled-vs-gold-plated-jewelry-explained/
(2) Heavy Metal Regulations in the US: An Overview https://www.compliancegate.com/heavy-metal-regulations-united-states/#Heavy_Metal_State_Regulations
(3) Rio Grand Sterling Silver SDS: https://www.riogrande.com/knowledge-hub/safety-data-sheets/102136-sds/
Rio Grande: https://www.riogrande.com/
ParaWire: https://parawire.com/