They have a drop chance of .05% meaning you'll get a single one every 2000 blocks. How much soul sand have you been digging?

 

nvm, I thinked about prismarine shard

 

Everything seems to be working for me - Thanks again Kuke for suggesting this awesome addition!

 

So you have around 9200-11500 blocks, which should have yielded around 7 or so shards at 0.05% (if I did my math right).

Did you happen to buy these inventories from spawn shops or have them laying around? If you placed them, McMMO drops aren't given I think, which might be the cause of the issue. Feel free to correct me if I am wrong.

 

Sounds like you either had really bad luck or it's not working. I can get in-game to check it out shortly.

 

more like 5.75. 11500/2000(0.05%) = 5.75. And placed blocks should give treasures.

 

I edited that :p missed a decimal place.

 

I have to ask - you do have over 800 excavation?

 

looks like the crystal drop is broken. I poked andrew about it.

 

You are the King of excavation then :p
And I just made another run and did not get any crystals either with 2 inventory full of soul sand. Of course Kuke already has taken care of it - as usual. ;)