Redstone ore has bold cracks

When I was mining in Survival mode, I mined some redstone and realized the cracks were too bold and looked weird instead of looking normal.
How to reproduce:
Go to Minecraft on a Windows 7
Be in Creative and place a block of Redstone ore and get an Iron Pickaxe
Go to Survival and mine the Redstone ore with the Iron Pickaxe
Look at the cracks as your mining it.