how to cure the granite flooring joints, makes better finish?

Question

we have laid black granite flooring. but the joints becomes an issue. if these joints are filled with cement or other compounds, it is not cured or finished properly and the look is bad as the filling is not even.
we need better suggestions to keep the floor better finishing.
edges are cut by machine, still gap is shown while laying.
valuable suggestions awaited. the flooring is done in kerala, india

Answer 1

Tiles grooming

Answer 2

use flooring paste...