Blacksmith/Shards
Shards File:Shards.png are a major currency that is used to upgrade items, unlike Gems and Coins, they can't be normally found in Stable Missions or in all Minigames, Shards can only be found in the chests from Dragon Tactics or by dismantling an item.
You can see how many Shards you have by going to the Blacksmith and look at the number by the re-rolling options. The number indicated in the red circles are your Shards and there's no other way to see how many do you have them besides that.
The only thing Shards are used for is for enhance purposes, in this case, to re-roll a stat or item. You can't buy anything with them and the only way to get more is by dismantling items or be rewarded with Shards in Dragon Tactics. But if you do run out of Shards, you can buy Shards for 
, 2 per 1 Shard.
