Good as Gold (and Silver and Platinum)
From carnelian to turquoise, we’ve covered a myriad of gemstones in this blog. But what about the precious metals in which these stones are set? Yes, we’re all familiar with gold, silver, and platinum, but there are still many questions that come up in terms of precious metals and jewelry – Where does vermeil fit in? What’s with 9kt gold? What exactly is white gold? What is rhodium plating?
This week, we’re answering these questions and looking into the differences between precious metals and the compounds that make them up.
Precious Metals: Chemical Elements vs. Jewelry-Grade
What exactly are silver, gold, and platinum? They’re all chemical elements you can find on the periodic table – each is a substance at its simplest and cannot be further broken down. However, it’s worth noting that your gold or silver jewelry is not pure gold or silver.
In their purest form, gold and silver are too soft to be used in jewelry. They scratch and dent easily and wouldn’t be good for daily wear. Jewelry is made of alloys – or, a metals combined with other metals to enhance strength and durability.
For example, sterling silver is only 92.5% silver (hence the “925” marking you’ll find on sterling silver jewelry). As pure silver is a malleable metal, base metals like copper, zinc, and nickel are added to help give it strength. “Fine silver” is 99% silver, but beware of other such fancy names. “German silver” is only 80% silver and “Russian silver” may reach 90%, but neither can be sold as “sterling silver” in the US as their silver contents are too low and may cause adverse reactions (such as tarnishing or green marks) in those allergic to base metals like nickel.
Sterling silver is often protected with a layer of rhodium plating. ‘This process of plating silver with a layer of white metal is called “flashing.”’ While we do not plate our silver jewelry at Gallery Byzantium, many sterling silver pieces are rhodium plated to protect the piece from tarnish. With time, however, this plating wears away. For this reason, rhodium plated pieces should never be cleaned with an abrasive solution or any ammonia-based products.
Platinum is 95% platinum (unless marked otherwise – “850 plat” is only 85% platinum, “800 plat” 80%, and so on. If it has less than 50% platinum, it cannot be marked as a platinum piece).
Gold is available in three colors: yellow, white, and rose (to keep things short, we’ll leave out Electrum, or “green gold” which mainly used in ancient times). While pure gold is yellow, it is mixed with platinum or palladium to bleach the color to a pale, pale yellow (almost white) and then rhodium plated to make white gold or mixed with silver and a high copper content for a rose color.
Gold.org has a great table that lists the metal contents on yellow, white, and rose gold. Click here to view it (please note that 9kt gold cannot be legally stamped as gold in the US as its gold contents are too low).
The Midas Touch
All that glitters is certainly not gold. While your true gold pieces will be stamped with a “14kt” or “10kt” depending on the gold content, you will see other pieces marketed as “gold-filled” or “gold-leaf.” But what does this all mean?
Peridot.com has the skivvy on everything you need to know about gold plating:
- Gold layered: Any layer of gold set over a base metal. It has no standard thickness.
- Gold leaf: Thin layers of gold foil (usually 22kt or 24kt for their malleability) hammered around another metal.
- Gold plated: A base metal dipped into gold. The gold quality must be at least 10kt and must be “at least 7 millionths of an inch thick.” Like rhodium plating, this gold plating will wear off over time.
- Gold overlay: Like gold-plated jewelry, a gold overlay is base metal dipped into gold (at least 10kt). Only, this time the gold content must be at least 5% of the total weight of the piece.
- Gold-filled: Contrary to the name, this is not filled with gold. Again, it is base metal covered by gold (of at least 10kt quality). The metals are then bonded together using heat and pressure. Because of this process, the gold will not flake or peel away.
- Vermeil: Sterling silver plated with a thick layer of gold (at Gallery Byzantium, our vermeil pieces are plated with 18kt gold). The best option for those sensitive/allergic to the alloys in base metals (usually nickel).
Platinum jewelry – https://www.consumer.ftc.gov/articles/0294-platinum-jewelry
Sterling silver vs. pure silver – http://www.jewelrynotes.com/sterling-silver-vs-pure-silver-what-is-the-difference/
All about gold jewellery – https://www.gold.org/about-gold/gold-jewellery
Types of gold – http://www.peridot.com/types-of-gold/
Tags: Gold, Jewelry, March 2018, platinum, precious metals, rhodium plating, rose gold, silver, white gold
Categorized in: Uncategorized