What would cause a gold ring to become brittle?

“My husband purchased a diamond with the help of Lesley a few years ago, the diamond is spectacular and it continues to take my breath away every time I look at it. He purchased the diamond loose, and then had it set by a local jeweler in a ring that is 14k white gold. I’ve never really liked the setting, not because it is not a pretty design, but specifically because there are all these tiny pits in the surface of the ring. The bottom of the ring shank has cracked several times, the jeweler says that this can happen where a ring has been sized, but lately it seems like the ring has become brittle and is falling apart. What would cause a gold ring to become brittle? And is there anything that I can do to prevent it?”

Those tiny pits in gold might be porosity:

I’m sorry to hear that you’re having issues with the wedding ring purchased from your local jeweler, but happy to hear that the Brian Gavin Signature round diamond that you purchased continues to be a joy! Although I can’t tell for certain without seeing the ring for myself, I think that the tiny pits that you describe might be porosity, which is essentially tiny holes created in the structure of the gold ring, as tiny air bubbles escaped to the surface of the ring during the casting process.

There are many different types of porosity, which take many different forms in cast jewelry, and there are a multitude of factors that can cause it, but suffice to say that substantial amounts of porosity can cause a gold ring to become brittle and break, especially if the piece is exposed to chlorine which is bad for gold. There is a really good article about porosity in jewelry and what the causes are available in the articles of Professional Jeweler, from which this picture is taken.

What to do if your gold ring becomes brittle:

Based upon my experience, the majority of the time, minor instances of porosity are not cause for concern and they do not tend to be a problem. However extensive occurrences of porosity can cause a ring to become brittle and break with time, and this seems to be the type of situation that you have described. I recommend having the ring re-made by a jeweler such as Brian Gavin who uses state-of-the-art casting equipment.

I realize that this might not be the advice that you want to hear, but I suspect that you might already be thinking that there is something wrong with the ring from a structural point of view. Perhaps there is a similar ring style available within our catalog of engagement rings, or you might take the opportunity to re-design your wedding set all together.

Mercury in thermometers can cause gold to break:

This might seem a bit random, but since we’re on the subject of things that can cause gold to become brittle, I might as well mention that exposure to liquid mercury, such as the type of mercury contained in old fashioned thermometers, will cause gold to become brittle and break. Many years ago, I had a client who had a thermometer break in her hand, the mercury flowed out into her hand, she washed her hands, washed her ring, and didn’t think much of it. Until she woke up the next morning to find her yellow gold ring, coated in silver, and broken into several pieces.

She brought it to us, quite distraught, and our bench jeweler took one look at the ring and said “Oh yes, liquid mercury will do that…” at which point she told us what happened. Very strange.