I have a ring that doesn't come off. Not in the shower, not while I'm out collecting samples, and not even when I play in the ocean. I got the ring after I started working in the environmental biz, so I made a conscious decision that it was going to get banged and likely scratched up, and I was ok with that. I don't take any other jewelery when I travel, though - I've gone through too many cell phone chargers and laptop batteries to trust that I wouldn't lose something.
I know that there are horrible stories out there about injuries caused by rings getting caught. So I kept an eye on the drillers and other contractors I worked with. If they were married, did they wear their rings, and if so, did they pick or avoid any particular materials?
Most of the drillers I know have tended to avoid materials that are not easily cut, such as titanium, so they can get them snipped in an emergency. They've generally just had plain gold rings and not worried overmuch about hands getting caught. There are other options, of course - using truly soft material, such as wood; getting a tattoo in lieu of a physical ring, or just not wearing the ring at all in the field.
Likewise, I think that most of the female geologists and other scientists who do fieldwork tend to keep their rings on, or in a pinch, wear them on a chain if they have brackets that may break or make it difficult to wear gloves. Of course, wearing things that dangle on a chain around your neck can cause another kind of trouble...