Rings are interesting things. Although I have gone through certain phases of my life wearing rings or not wearing any rings at all, the reasons folks have had for wearing rings throughout prehistory and history is a fairly new interest. I suppose it started when I noticed that a Canadian couple I met in England wear their wedding rings on the ring fingers of their right hands, instead of the more common American practice of wearing them on the ring fingers of the left hand. An interesting discussion of such things can be found on this blog : https://humanpast.wordpress.com/2013/10/30/rings-and-things/
Shopping in an Atlanta charity shop recently, this lately dormant interest was reawakened by a serendipitous find. What is evidently one of the classic works on rings is now happily in my possession, and is an amazing introduction to the history of rings up to that time. Rings for the Finger: From the Earliest Known Times to the Present, with Full Descriptions of the Origin, Early Making, Materials, the Archaeology, History, For Affection, For Love, For Engagement, For Wedding, Commemorative, Mourning, Etc. (1917) by George Frederick Kunz is nothing if not an in depth treatise on the myriad mysteries of rings!
It seems that among the men of ancient Rome only senators were allowed to wear gold rings until later in the Empire when the cohesion holding together the social fabric began to melt and it became all the rage among all classes. Also, prehistoric peoples of the southwestern Native American tribes wore rings made of shell, some being incised with natural images like lightning and clouds. Pre-columbian copper rings have also been unearthed in Indian mounds in Ohio, and a few stone rings, which I must presume were made of soapstone (steatite) have also been excavated in Kentucky, Tennessee, and other states.
Kunz thought that the custom of wearing rings in the Occidental world derived ultimately from the Orient or from the Egyptians, who reduced seals of rank worn about the neck or arm to rings for the finger. From Egypt the practice spread to Greece and to the Etruscans, from whom the Romans adopted it. There are even mythological tales of ring-wearing, such as the one in which Zeus freed Prometheus but commanded him to wear a ring made of one of the links of his Caucasian chain set with a tiny piece of the rock to which he had been chained. In this manner his 30,000 year punishment could continue in a manner more healthy to his liver. Yes, Prometheus had his own beast of burden, and it had nothing to do with alcohol!
“Three Rings for the Elven-kings under the sky,
Seven for the Dwarf-lords in their halls of stone,
Nine for Mortal Men doomed to die,
One for the Dark Lord on his dark throne
In the Land of Mordor where the Shadows lie.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all, and in the darkness bind them,
In the Land of Mordor where the Shadows lie.”
J. R. R. Tolkien, The Hobbit, 1937