EDIT: Do what @BrettPlayMC said down there

 

Please use the script request format:
https://forums.skunity.com/threads/format-script-request-format.170/

 

Edited with the right request format

 

I can do this for you pretty quickly. What ores do you want?

 

Here ya go! (This skript was made by one of my old friend who left MC, and the one who got me into Skript. )

Code (Text):

1. on block form of cobblestone:
2.     chance of 1%:
3.         set event-block to diamond ore
4.         stop
5.     chance of 10%:
6.         set event-block to gold ore
7.         stop
8.     chance of 15%:
9.         set event-block to iron ore
10.         stop
11.     chance of 40%:
12.         set event-block to coal ore
13.         stop

 

Altho what you wrote WAS correct, unfortunately, it doesn't work for whatever reason. I was aware of this but for whatever reason it does not work for me. Thanks either way, you have +rep from me

 

Hmm... it worked for me... weird...

 

Might be due to another skript, don't know, I'll check it out later and I'll tell you for sure