Maker - Alchemy Skill FAQ and Walkthrough

You used mid range crystals when making, otherwise it would have added +5 to Dex and Luk, right?

How come you could only use 2 of the 4 slots? Oh and can you put in 4 of the same crystal ?

Yeah, he used a mid-grade STR and Mid-grade DEX crystal on that.

He can only use two slots because his alchemy skill is at level 2. I can only use one slot because My skill is only at level 1. Since the skill can only reach level 3 right now, the most crystals you can use are three.

No, sadly, you can apparently only use one of each type of jewel (One diamond, one STR crystal, etc.). That means one Diamond, regardless of grade. So you could use 1 Low grade, or 1 high grade, but that's the only diamond you can use. Not both.