u/CMDR_Lupin

I have a few of these small pucks of wood, and want to turn them into the ring box to propose with. After cutting them from the original branch, they cracked shortly after. Need help keeping them from cracking like this, and how to seal them for long-term stability. Any help is appreciated, please and thank you.

Also, it's Chinese Red Birch, and about 3-4 inches in thickness depending on which puck.