Alchemist will tell you that have to collect 10 Dragon Shards and bring them back to him.
After you collect 10 Dragon Shards, return to the Alchemist. He will give you a Cor Draconis. From this moment you will have the Dragon Stone Alchemy and the ability to create Cor without returning to the Alchemist.
or 
button. You can also open it with the letter O. 
You can upgrade your Dragon Stone at the Alchemist.
There are 3 kind of upgrades:
• Class
• Clarity
• Level
The Class raise the intensity and the number of bonus. The Class are, Rough, Cut, Rare, Ancient and Legendary.
To upgrade the class you must socket 5 stones of the same type and press Refine
The Dragon Stone may go to the next Class, stay at the same Class or advance to the next. In both case of success or failures you will only receive one Dragon Stone.
The Clarity raise the intensity of the bonus. The Clarity Grades are, Minor, Low, Intermediate, High and Super.
To upgrade the Clarity you must socket a minimal of 4 Dragon Stone of the same kind. The higher the rank, the lower the stone needed. Even in this case, the upgrade may leave the current Clarity Grade, reduce to the previous or advance to the next.
The level raise the ammount of bonus given by the Dragon Stone. The max level of each Stone is based on the Class level. Rough Dragon Stone are maxed at +2 while Legendary Stone at +6.
To upgrade the level you need a special item, the Dragon Bean.
- Green Dragon Bean, dropped from the metins from level 95 to 105.
- Blue Dragon Bean, higher success but dropped only from Nemere the Ice Lord.
• White Dragon
• Fire Dragon
• Wind Dragon
• Iron Dragon
• Thunder Dragon