It's been asked several times, so I thought I would weigh in on the proper way to wear signet ring, according to tradition. In the British tradition, the signet ring is normally worn on the pinky of nondominant hand. There was a practical reason for this. By wearing it on the nondominant hand it doesn't get in the way of the dominant hand when writing. Which in medieval times was a visible sign that you could write, and had people to write to. In wearing it on the pinky, one could turn the ring 90° and make a seal impression without removing the ring. This means that the crest would face inward, toward the wearer. It was considered the mark of a gentleman to have one, which is why you see so many British nobility, military guys, and American old money back in the day wearing them. The signet was to be small, and not ostentatious. It was the crest engraved upon the ring that carried the status--not the ring itself.
Pinky rings got a reputation among Mafiosi, because those groups had pretentious of nobility (hence calling a Godfather "Don.") But because most of these guys were uneducated, they tended to overdo the display into a demonstration of status, authority and dominance, not of class and social mobility. Kissing rings as a sign of submission and homage is a Continental thing. It went out in England after Magna Carta.
When I became a Past Master of my Masonic Lodge, I got a simple small signet and started wearing it on my left pinky. It is very comfortable there, and doesn't get in the way when I write or sketch. Very practical.
I am thinking about purchasing this estate sale gold ring. It has a smooth 14k gold band (about 15 grams) surrounding an oval bloodstone with a small centered diamond. Based on the shape and style, does anyone have any idea of what era it may have been made? I will most likely buy it so my question is pure curiosity.