You can either use the crossbow and rope to cross the cemetery, or drop into the red fire barrier by hanging over the cemetery and taking off the lid of the grave to get the jewel. There will be a clock puzzle in the room. There is a clock to the left behind the wall paper. Press the buttons in the following order: 3 o'clock, 12 o'clock, 6 o'clock, 5 o'clock. You can now get the Golden Cross.
In the stone room, use the steps in the following order: 1, 3, 6, 7, 9, 10. Note: Refer to the the second step as 1. If done correctly, you will hear the sound of something unlocking. Go to the left. Use the skull from your inventory on the hand, then use the crowbar to break the skull and obtain the jewel.