In North America and the United Kingdom, the engagement ring is traditionally worn on the left hand ring finger. The origins of this custom might lie in the ancient Egyptian myth that this finger contained a vein leading directly to the heart, or it may simply be due to the fact that the heart lies slightly to the left side of the body. Conversely, in Poland and Ukraine, it is customary to wear the engagement ring on the right hand. In Germany, the ring is worn on the left hand while engaged, but moves to the right hand after marriage. In other words, there is no single truth or one general rule. It is simply a matter of culture, tradition and personal style.
When it comes to material there are no strict regulations, although it seems that gold is still the main choice. Muslim men, however, do not have this option to wear a golden wedding ring. Muslim law says it is forbidden for them to wear gold. Only women can do so.