When I germ it usually takes about 3 days to pop from coco/rapid rooter in a humidity dome and light . Depending how long I had the seed or how old your seed is i usually give them 10 days max in 75-80 degrees temp 70RH or higher
Sometimes the seeds have a harder shell than others, not always a duff. Just give a slight gentle squeeze on the shell so as to crack it open. If it doesn't germinate then, it's a duff