What is Rhodium? Why is it used in Jewellery?
First things first. Let’s clear up what this mysterious rhodium is. Rhodium is the rarest of the 6 platinum group metals and only occur in up to one part per 200 million in the Earth's crust, Why is that? Well, because it is very rare in nature, it is only found as a by-product of mining for other metals, such as platinum. This, unfortunately, affects the price of rhodium making it very volatile as its availability is connected to platinum supply and demand.
As we’ve said, the price of rhodium has huge ups and downs. Sometimes it can rise to ten times the price of gold – usually when platinum is not mined as much because of a drop in demand. Other times, rhodium prices drop much closer to the price of gold or platinum. Because of the complexity of the situation, rhodium is not the most stable of investments. Another reason why it’s not used for much more than plating is that, when pure, it is brittle and not very malleable.
While rhodium is both too expensive and too brittle to make jewellery out of, it makes an excellent plating material. It is often used to lend a higher sheen to silver or white gold pieces. Being harder than both silver and gold, it also makes an excellent protective coat that shields jewellery from scratches.
Sterling silver is a white metal and does not need rhodium plating to acquire its color. However, sterling silver is prone to tarnish over time, which is caused by the exposure to sulfur in the air, and forms a dark silver sulfide on the surface. Since rhodium does not tarnish, it is often plated over silver in order to preserve the silvery-white look and prevent it from darkening over time. As the plating wears off, the white of the silver will come through, but will not be noticeable like gold. Those exposed sections may acquire some tarnish but this can easily be polished at home.
Because rhodium plating is hypoallergenic, you won’t get skin reactions by wearing rhodium, which is perfect for people who struggle with reactions with earrings. However, it is best to note that while rhodium itself will not cause any rashes, white gold often contains nickel in its alloys. As the plating wears off, you may well be exposed to nickel allergies as your skin comes into contact with the original base metal.
So there we go, a brief insight into rhodium and its uses in jewellery. Why not take a look at our rhodium finished sterling silver jewellery HERE.