I agree....Being a silkie cross which are nearly always early hatch, and now overdue, without peeps or movement, i would say that it's probably a fully formed chick that suffocated in the shell instead of pipping the internal membrane.
3 options-
1 wait (not recommend)
2 toss it
3 open the middle of the clear end very carefully.
If you do this and the membrane around the chick looks dry then it is dead.
If it's not dry looking , then the chick should move a bit as you gently shake the egg. If not- it's dead.
If it does respond then keep it really moist, putting a single drop of water into the egg using a cotton tip every hour until it stars making noise.
From there you need to follow assisted hatching procedures as it very unlikely to come out on its own.
Is there fluid floating around the top of the chick underneath the membrane??I tried this. Very careful to leave inner membrane intact.
The chick itself doesn't move but the membrane did not appear dry.. Keeping it moist under heat lamp and wet cloth. What do you recommend?