Dark Crystal Ore : How do I process it? (Help me pleeeease!)

[Yang-chan]

I just bought a dark crystal Ore and went down to the 'Holy Ground at the Snowfield' and realized it doesn't work. =_____=;;
Where do I go to make my dark crystal ore into an actual 'dark crystal'


~thanks  

[LilFangLi]

you need 10 crystal ores then go to the ore refiner in el nath market and refine it