That is correct. Characters are now able to choose one elemental stone which they can equip to their weapons. I have yet to add the typed out guide on the boards, but for the most part it will be similar to this table.
A change will be the levels (Low 1-4, Mid 5-9, Max 10) instead of just 1, 5, 10.
Stones fall into three categories -
Basic Elements - Earth, Wind, Water, Fire
Combination Elements - Magma (Earth and Fire) and Ice (Water and Wind)
Advanced Elements - Light and Dark