What material is this and can it be repaired

[rt160001]

I have a 1994 Regal Valanti 240. The companion way lid/door/cover is cracked. It is where the cabin lock is located and used as the walk-thru to the bow. It is 3/8 thick and very hard, dense and strong. I thought it would be starboard, but I purchased some starboard but it is not the same material, it is not as dense or hard and has a different appearance then the cracked "hatch" door.
What is this material and can the crack be repaired?
Where can I purchase some of this stuff?
Can this material be bent using heat or other means?
Thanks
Randy