How to tell if tungsten ring has cobalt? Why we should avoid buying a tungsten ring made with cobalt? What would happen if your rings made with cobalt?
People love the tungsten carbide ring because it is made to last. A normal tungsten ring will last for more than 30 years without losing its luster and gloss. So many people buy it as a wedding band.
The last post, you guys learn how to Tell if a Ring is Real Tungsten? (4 Methods that Work), so this post I will give you more tips on how to tell if tungsten ring has cobalt or not.
Let’s begin with this question:
Why we should avoid buying a tungsten ring made with cobalt?
Cobalt is a cheaper filler that the tungsten ring manufacturer uses to make the tungsten ring. Here is a table of Tungsten VS Cobalt.
There are many downsides if you have a tungsten carbide ring made with cobalt in it. The cobalt in the ring will react with your sweat( natural oils) produced by the skin. Cobalt rings can blacken your finger and the ring will develop some permanent oxidation spots that you can never remove.
Just as the picture shows below, the ring looks great at first, but soon or later, the chemical reaction will occur and this is what would happen.
So, we should avoid buying a tungsten ring made with cobalt.
How to tell if Tungsten Carbide ring is bound by Nickel or Cobalt alloy?
1.Precise measurement to distinguish them.
This is a very hard question to answer.
Why?
Cobalt and nickel are almost the same density. See the data below.
Cobalt Density: 8.86 grams per cubic centimeter
Nickel Density:8.908 gram per cubic centimeter
Because of the density, you need a very precise measurement to distinguish them.
There is NO easy non-destructive way to do it.
So, you can use an SEM to spot check the ring. But, you need a friend who works in a lab…
Therefore, this is a way I do not recommend.
2.Price- Sometimes the price won’t tell a lie.
As you know, the tungsten ring made with cobalt is cheaper than rings made with nickel. The best way to make sure you get a premium tungsten ring is to get a lifetime warranty from the seller. So if your ring made with cobalt, you can get a free replacement.
3. Ask the seller – This is the only way I recommend.
Before you place the order online, you really read the product description carefully. If you are not sure, ask the seller. Check this one on Amazon, the seller tells you that the ring is cobalt-free. If you buy a ring at a local store, you can contact the retailer and ask them if the tungsten carbide ring contains cobalt.
Most of the time, the tungsten ring is labeled with what is have been alloyed with. The majority of the tungsten rings on the market are labeled as” Cobalt Free”
Main Take way: If you get a tungsten ring, you are not sure, please call the retailer who sold you to reconfirm. If they fail to tell what type of alloy the ring is made from. I suggest you return the ring and to get a new ring from a seller who knows the ring being sold and answer your question correctly.
Summary:
There are not many ways to test a ring made with cobalt. This is the way I know. I really hope the methods can resolve your concern.
But, as a tungsten rings maker, I can tell you, I never make tungsten rings with cobalt. So, most of the ring on the USA market is a premium tungsten ring.
You get what you pay for. So. If you got any problem, contact your retailer directly. Ask some questions.
Thank you, guys. This is a short post. If you want to read more posts, read them here or here.
Tiger is a fashion&jewelry lover. He is also a fashion jewelry manufacturer that help thousands of small business to grow and also do business with some big fashion jewelry brands. He is a truly metal expert and he will share some information you are looking for.