Answer: Yes, and it’s very easy. You can either put the stem in a glass of water or stick it about an inch deep in damp potting mix. Remove any leaves that would be under the water or below the soil first. If you’re using potting mix, add water only when it is nearly dried out.
In a couple weeks you should see roots forming in the water; once a handful have formed, pot the stem up. If you’re rooting it in soil and you tug gently on the stem in soil and it resists, roots have formed.
You can also propagate a jade by sticking one of its leaves, stem end down, in potting mix or moist sand. After some time it will resist a gentle tug. Some time later a tiny jade plant will appear from the base of the leaf. I’ve tried all these methods and this takes much longer than rooting a stem.