This magnificent  Indian ring OM is  made by craftsman from Jaipur, India.

It is made of brass (an alloy of copper and zinc). Brass is a good alternative to gold, it  does not change color and does not break down over time. It  does not cause allergy, so you can wear it without fear.

They are  very easy to clean by rubbing it with a little bit of toothpaste or soap and lemon juice.
 
The size of the ring is adjustable.