I’ve been thinking about the person who bears the brunt from the one who is jealous. This person needs help too. If it were me, I would confront the jealous person in a gentle manner. I might say,
“Are you angry at me? Did I do something to offend you? I feel mistreated by you. Could it be that you’re jealous?”
If the situation involved someone I cared about, I would offer them a compliment; verbal or in writing. Some people react well to a card that says you’re special.
This is as far as I would go with trying to mend such a relationship. I don’t recommend that “you” fix other peoples problems but in this situation it’s also “your” problem. Lastly, I would recommend that they read my book!