Where can i buy shards?

[ArenaGrenadeVEVO 2]

i have been to agate circus and i cant buy things because i am low on shards. Each time they tell me i can buy them at the front counter but i have talked to every person there and nobody sold them. Where can i get them from by using money? Im now supposed to fight adrienn, so if its a thing you unlock after beating him, please do tell me. Also please dont be vague by just saying agate circus and/or 7th street. Can i know the exact location

[Velthomer21 39]

It's something that you can't do after you leave Agate, I believe. You can still go fight the clown in the rainbow challenge to get some free shards, though.

[seki108 1226]

I think buying shards was removed in Ep 16, possibly earlier since the option wasn't there on my Reborn playthrough.  Now you just find them or fight the clown for them.

[Luna 5]

The agate rainbow clown gives u shards for defeating him u can farm shards that way or by mining but i would only do the mining method if u have all fossil and the odd keystone cause those stuff are only available trough mining.