Signet is considered one of the most common jewelry. The oldest discovered by archaeologists rings are made of mammoth tusks and there are 21 000 years.
Later, as the materials for rings were used wood and stone. Learning to handle metal man began tinkering ring and out of it.
In ancient times, a large widespread poison rings, equipped with a small container in which it was possible to hide the poison, to pour it in case the enemy in food or drink.
Modern rings are usually made of metals: gold, silver, stainless steel. As with the insert can be used gems and jewelry glass.