Does white gold change colour?
Many of my clients over the years have asked that exact question - "does white gold change colour?". As such, I decided it would be good to write a short piece on this to give as much information to the client as possible. If you have all the information, you can make the decision which will best suit you.
Let's start with the why behind this...
Pure gold is mixed with other metals to give it strength
Pure 24ct gold is a beautiful yellow colour, it is however very soft in it's pure state and therefore when used for jewellery, is often mixed with other metals to give it strength. Looking at the gold alloys used in jewellery manufacture - 18ct gold has 18 parts pure gold in that 24 parts alloy, while the remaining 6 parts are other metals. 22ct is 22 parts pure gold out of 24 part alloy, 14ct is 14 parts pure gold out of the 24 part alloy and 9ct is 9 parts pure gold out of 24 part alloy.
The other metals used can change the colour of that gold alloy
When creating 18ct yellow gold (for example), the metals used in this remaining 6 parts are yellow metal - thus keeping the yellow colour. When creating 18ct white gold on the other hand, the metals used in the remaining 6 parts are white metals. By adding white metals, we are turning the colour from yellow to white. The resulting colour however, is not white, it is more of a warm greyish colour. This colour in my opinion is beautiful and I often use it in designs showing off it's naturally beautiful colour.
If however we (the jewellery trade) are setting white diamonds in white gold, the best white colour for showing off ice white diamonds is ice white metal. The white gold is therefore plated with a naturally white metal called rhodium. This forms a surface coating over the white gold, of the white metal rhodium. Almost all white gold pieces produced in the UK are plated with rhodium.
Why does my white gold piece look like it's changing colour?
Because most of the white gold pieces in this country are plated with white rhodium, when the jewellery is worn, this plating begins (slowly) to wear off revealing the natural warm grey colour of the white gold underneath. In the example of a ring - the rhodium on the back of the ring where it gets most wear, will be the first area to go. So it may look like it is changing colour, but it is really the rhodium plating wearing off so you can see the natural colour of the white gold below.