Is this Gold or Silver or other material?

by K Bonikowsky
(Hope, BC Canada)

I was given this bracelet to be made into a ring and I am not sure if it is gold or silver or some other material!? There is a symbol inside that I can't quite make out. It is about 40 - 50 years old and I was told that it was bought in Mexico?

Please let me know if you can figure the material out!
Thanks