I don't know if this was changed in the full release but as of right now I am in a shared world with a friend and normally I would grind for materials.
It been 35 in game days and I notice that none of the Marble and Quartz Shards are respawning in any location I found them in.
Red Ant Hill: none
Small ant hill near the tree: none
Small cave with red mite: none
I don't know if it a bug or intentional or it bugged by shared world but it would be hard to upgrade with 2 people even when one person always tend to upgrade everything they get.