powder can be taken back to a crafting station and fashioned back into
a brick, but the recipe requires 9 of the powder for a single brick.
It's important to note that these re-built bricks will only yield one
powder again if broken.
The bricks can be used as a light source though! Much dimmer than a
torch or jack-o-lantern, but also capable of being placed underwater. I
believe they'd make a very nice illuminated walkway in a future