Soo I wanted to learn a little bit about their history :)
This website says the idea began in the 1970s. The church wanted a "badge of belief" for the youth, but necklaces and the like weren't gonna work because guys would never wear them. Rings, however, those would work. They're small and relatively inconspicuous, and they can be gender-neutral.
Did you know the original CTR ring was a gold-colored ring with a green shield with CTR in the middle? You probably did. I didn't, though :) the website cited above explains why a green shield was chosen:
The idea for the shield seemed a was thought of as to shield its bearers from temptation, and the green background of the shield was used to symbolize the evergreen tree – a tree that stays true to its appearance as the seasons change.
Side note, I love how I start out talking on one topic, and then I get sidetracked when I make a connection like the one above. Also, gold is virtue. I couldn't find a place in the website that talks about why they chose gold, but to me it seems like a good reminder of virtue and of purity. If you always choose the right, you can remain pure and untainted by sins. Granted, it's pretty much impossible to be sinless (only Christ was sinless), but this ring is a reminder to make an effort.
My CTR rings don't look anything like the original one shown above. I took a poor quality picture of them for this post, but here's the official pictures from Deseret Book
The first one, a "Blossom Square-Top CTR Ring," is more bold and obvious. I get a lot of comments on it. The flower makes it look very feminine, and also brings to mind the value Knowledge. Wait, what? Why? Well, Knowledge is green to remind us of growth, how we should always be growing in our knowledge and learning more (source). Get it, flower, leaves, growing?
Anywho, so that didn't end up being very much about the history, but we went off on a tangent about symbolic meaning, so that's okay :) Do you have any CTR rings or other pieces of jewelry that are special to you? I know some of you do, you mentioned them in comments on Self-Adornment :) so now I want you to tell me about them more in-depth! Who gave you your CTR ring or that special necklace/bracelet you always wear? What major events do your pieces of jewelry remind you of? What symbolic meaning do they carry?