Gold is one of the most common jewelry metals out there, and it’s likely on your ring right now. Sometimes the gold is of great quality, like a higher karat or it has a thick plating, and sometimes it’s not so great, leading to oxidation or tarnishing. The result is a black or green stain on your skin, and also on your jewelry.
So why is that gold ring or necklace turning black ? Is it fake gold ? Does gold tarnish at all ? Let’s find out.
Why does gold turn black ?
Gold can turn black if it’s a lower karat, and mixed with nickel and copper, which both react to your sweat or chemical products like perfume. Pure 24k gold does not tarnish at all, and lower karat gold has more metal alloys in it, which can lead to tarnishing or blackening.
Nearly all gold jewelry on the market is actually a gold alloy, with varying amounts of pure gold in it, as dictated by the karat stamp. The most common karats are 14k and 18k , which are 58% gold and 75% gold, respectively. The higher the karat, the softer the jewelry, and thus it’d be less likely to withstand constant wear and tear.
The metal alloys in your gold matter
What your jewelry has as a metal alloys is critical. Most gold jewelry uses silver, copper, and nickel as part of the alloy, but you may also find palladium or rhodium in the mix. Pure gold is very soft, easily bent and a gold ring made of pure gold would be bent out of shape pretty quickly. So a metal alloy is introduced to protect the jewelry, make it sturdy, and is also conveniently cuts down the costs.
Silver tarnishes but may easily be cleaned. If your gold piece has a high amount of silver in it, it can turn a little black as silver oxidizes black. You know how silverware needs to be polished ? A similar thing happens when silver is the main alloy in gold jewelry. If the tarnish is from a lot of silver, it won’t usually stain your skin.
Copper and nickel turn black-green when oxidized, and this usually gives more of a green color. This is the kind that may also stain your skin if the gold is of a very low karat, or if the gold is just plated and the plating is very, very thin.
The gold plating could’ve worn off the jewelry
Not all gold jewelry is made of gold alloy, some is made of a base metal onto which gold plating has been applied. Plating is usually doe vie electroplating, and can be of various thickness. The thinnest is 0.5 microns, as that’s the bare minimum considered as a gold plating. For context, 1.0 micron is 1/1000 of a millimeter, and 0.5 microns is 0.5/1000 of a millimeter.
If your jewelry has thin gold plating, is will wear off within a few years, and may reveal the underlying material. If copper is present, it will usually bond with the gold atoms quickly and tarnish the jewelry pretty quickly.
How to clean tarnished gold
If your gold is tarnished it can be fixed, in that it can be cleaned and return to its original color. it may still require professional polishing or cleaning after wards, depending on your tastes and how tarnished the gold is.
To clean your gold jewelry, get a soft cloth, and use warm soapy water (don’t go overboard with the soap). It’s the rubbing motion you do with the cloth that helps remove the tarnish, more than the soap itself.
If you have a very soft brush, like the softest toothbrush possible, you can use that to get into every nook and cranny. After you’re done cleaning the jewelry, rinse it one more time in warm water, and pat it dry with a clean cloth or paper towel. Let it air dry further if it needs to.
Does vinegar harm gold ?
Vinegar does not harm pure gold, or gold pieces with higher karat. So anything at 18k and above should be safe, but we cannot vouch for 14k gold, or lower. Vinegar is an acid, and the gold atoms do not react to it. But other metals present in the alloy may interact with it. This means your jewelry could be damaged if it’s lower karat when submerged in vinegar.
Higher karat gold does not tarnish
In general the higher the gold karat, the more gold there is in that particular jewelry piece. Pure 24k gold is soft, malleable, and is not fit for everyday wear. It’s beautiful and has a deep golden color, but it’s not good for everyday use. Only wear these pieces occasionally. Do not set very hard, strong gems like diamonds, sapphires, or rubies in pure gold, they will be easily lost and may damage the gold.
If you’re looking for a gold alloy that will be durable and still look wonderful, you have two options: get it plated thick, or get a higher karat.
Say you decide to have it plated. It could be any gold karat alloy, or any base metal for that matter. As long as the outer layer if a thick gold plating the ring will last a long, long time. The thickest gold plating is vermeil, which is at least 2.5 microns. For reference, standard gold plating is 0.5 microns.
And if you decide to get a higher karat gold but not 24k, we recommend 18k or 20k. An 18k gold has 75% pure gold in it, while 20k gold has 83% gold in it. This is the sweet spot between a metal that is too soft but looks very similar to pure gold, and a metal that is very strong and sturdy but looks less impressive.
Keep in mind that 18k gold is more commonly found in jewelry shops, but some may carry 20k. You can always ask a jeweler to make a ring for you, according to your size and metal preferences.
I’m the main author for jewelrymaterialguide.com. I started this site after we did tons of research before our wedding and noticed that there is information about rings, jewelry, and so on that is really hard to find on the internet.