Heavy Core 100 Hardness block

I think the heavy core could use some other content. Ive always wanted a really strong block that could be moved by pistons for vaults and other bunker applications. The heavy core provides a great opportunity for this. Perhaps crafted from 4 or 9 heavy cores you could make a vault or bunker block that has 100 hardness (twice that of obsidian) and can be moved by pistons. would be a lot of fun on smp servers. Thank you for your time.