[Skyblock] Granite in the Hero island yet you can't obtain it

Your username: NetherChan
In which minigame/server does the bug occur: Skyblock 1, Skyblock 2 and Skyblock 3
Detailed description of bug: So basically, what happens is if you notice the Hero island at spawn, it shows that it has Granite in it. When I tried to create a island so I could get it, it ends up becoming Stone in your inventory once you mine it. This is not a texture pack glitch for I've tried it with different texture packs (including the default one) and it shows the block as Granite. Some pictures shall be provided down below to give more or less a brief explanation on what's going on. As seen by the pictures, it shows that with both a texture pack and the default one, you can still see Granite instead of Stone.

 

I'm not sure why this visual glitch is happening. The server clearly thinks those blocks are stone, but yet the client displays them as Granite. I don't think there's much I can do about this, but it shouldn't really matter anyway.