Purpose of sharp black crystal shard?

[SweenMachine]

The description says grind two to obtain 1-3 black weapon stones, but weapon stones are 300k each in the market and a single shard is 3.5mil so there must be some other use for them. Thoughts?

[Suzaku]

The description is wrong. What you do is heat them with a pair of their respective black stones (sharp with weapon, hard with armor) to make Concentrated Magical Black Stones. These concentrated versions are what is used to enhance gear beyond +15.

[zzirf]

thanks Suzaku

[SweenMachine]

Oh ok thanks, perhaps that's how I upgrade the orange kriegsmesser with a roman numeral I that I bought from the market yesterday. Was confused as to why it as a viable upgrade item but it wouldn't let me use the normal stones. I'll try that out, thanks!

Side note: Wish I knew this before seeling the 4 or 5 of each type I already had from events and login bonus :S