Creativerse tooltips R40 037 stone blocks crafted
Creativerse 2017-05-17 01-42-03-69 crafting recipes R41,5 blocks
Creativerse unlocks R43 2017-06-11 13-14-38-232 blocks stairs roofs

The Stone Floor is a grey tiled building block that looks like it's made of 8 smaller stone blocks.

It can be crafted in your Crafting Menu (default key "q") after the according crafting recipe has been unlocked by

To craft 8 blocks of Stone Floor at a time, you'll need (as of R44 in June 2017):

Creativerse building blocks0100
Stone Floor
Crafting Stone Floor is one of the unlocking requirements for Stone Block Wall.