For referance the relic of chi ji gives more int than any other healer trinket in the game inside challenge modes but its not worth almost 600 int. I also have int enchant on bracers on one char and mastery on the other but its still only about 300 int total with the trinket. I cant figure out where the remaining int comes from so im going to asume the gem works but is scaled down.
EDIT: Nevermind I looked into it further and there seems to be a 67 int discrepancy in the end when all things are considered. Only problem is that 67 int difference should not exist.