We’ve all been there – received a beautiful new tungsten ring, worn it for a few days, and then noticed that faint green mark start to appear. With tungsten carbide gaining popularity as an affordable alternative to the precious metals usually found in rings and other jewelry, you may be wondering if it’s too good to be true. Will tungsten rings turn your fingers green?
What is tungsten?
Tungsten has the highest melting point of all metals, at an incredible 6,191.6 degrees Fahrenheit, and is second only to diamond as the hardest substance on earth. Tungsten carbide is 10 times harder than 18k gold, and is the most scratch resistant metal known to man. However, tungsten carbide itself is a powdery substance and requires a bonding material to hold it together. Most tungsten jewelry actually consists of about 85% tungsten carbide.
Why might tungsten rings turn my finger green?
Tungsten rings can be made using one of two different bonding materials – nickel and cobalt.
Cobalt is a cheaper metal than nickel, and can cause irritation when it comes into contact with skin. Additionally, nickel has a tendency to oxidise – a chemical reaction to the air – which causes it to change colour and results in the ‘green’ effect on the skin, as well as tarnishing and discolouration on the jewelry itself.
Nickel, on the other hand, is more expensive, but will also last a lot longer and doesn’t carry the same risks of irritation and discolouring that cobalt can cause. While it is possible for people to have allergic reactions to most nickel metal alloys, such as those found in gold jewelry, tungsten and nickel alloys are hypoallergenic. This is because the tungsten binds with the nickel so tightly that the nickel cannot react with the skin.
How can I make sure I get the right kind of tungsten?
Tungsten wedding bands may contain either cobalt or nickel as the binding agent – unfortunately, there’s no easy way to tell which one, just by looking at the rings. You’ll need to ensure you check the details of the alloys used in a tungsten ring before you purchase – and if you’re unsure, check with the jeweler or manufacturer. As long as you choose a nickel alloy, you can be assured that your tungsten ring won’t turn your finger green.