Why Doesnt Marble Have A Foliation Regardless Of Grade
It is because they are made of only one mineral. The higher quality stones have no holes that need to be filled with epoxy or resin. Some stones such as thassos white marble will only have fill in the lower grades.
Schist Is A Metamorphic Rock With Well Developed Foliation It Often Contains Significant Amounts Of Mica Which Allow The Rocas Metamorficas Metamorficas Rocas