Deleting Shards
From the GameGlass Hub simply navigate to the library tab, click on Shard and then click the delete button on the top right of the menu.
To confirm deletion, click the delete button a second time which appear to the left of your cursor's position.
Copying Shards:
You can copy shards which you have created in the Forge by clicking the clone button directly to the left of the garbage bin icon. This will create a new Shard labeled [copy]