Mined "Emerald" with iron pickaxe and didn't get a emerald.

Put the summary of the bug you're having here

What I expected to happen was...:
To get an emerald after mining with iron pickaxe.

What actually happened was...:
I mined the emerald ore block and didn't get anything except EXP

Steps to Reproduce:
1. Start on flat world tunnelers dream.
2. Mine emerald with iron and diamond pick.
3. In survival Hard mode locked.