Chalk, granite and other useful stones

Would be good to have some more stone types generating in large patches, so players would build mines for them once they find a deposit. However, it should not litter the ground like in MC or similar, but to be found rarely. Each new stone type should have specific properties which make them actually different beyond the texture.

Several ideas for inspiration (not a plan):

Chalk. Soft and oddly breakable by hand. Useful as white building material and to make white dye. Only common close to the surface.
Gypsum. As an alternative to Chalk. Nodes drop a powder which needs to be processed (furnace and adding water) to turn to full nodes again.
Granite. Harder than normal stone, requires a copper pick at least. Some precious ores only occur in granite. More common the deeper one goes underground.
Sandstone in mapgen. Sandstone is already there, in mapgen it can be a cheap building material, diggable by hand.
Pumice. Floating on water, created by lavacooling. Otherwise boring.
An exotic material with antigravity (falls upwards).
Fossilized plastic. As if from a dead civilization some millions of years ago.

CasimirKaPazi / Voxelgarden

Chalk, granite and other useful stones #42