Refined Stone
To create Refined stone you will need to go in Aida at coordinates 78 13 and talk to NPC called Osbourne

At the beginning it will give you warning, read it and click OK to continue.
In the 8 x 4 Chaos storage area, place:
* One (1) or more Item(s)
Press the Refine button.

If the combination succeeds, one Refined Stone will be created.
If the combination fails, the item(s) used in the combination are destroyed.
You can get two types of Refined stone:
Low refined stone

High refined stone

Which type of stone you will get depends of what item you will put, better item better stone.