It's Cartier, it's solid 18K, and it feels like a dream when worn. What can be better??

This is one of their iconic Ellipse rings, made in 1993. As you can see from the images, it's fully hallmarked and has a serial number. 

The Ellipse ring refers to that it's slightly heavier/domed on one side. It's subtle, but chic.

It's a size 7.75, and if you sized it at all, you'd definitely lose some of the hallmarks. It weighs a heavy 13.83 grams.

I also love it stacked, as you can see in the last photo. I have it stacked with a Mauboussin ring, which is sold separately.  This is a forever ring!