Sand and gravel disappear when the falls on a torch. They should be and item then!

Put the summary of the bug you're having here
Sand falls on a torch and disappear.
What I expected to happen was...:
Describe what you thought should happen here
It should drop sand as an item
What actually happened was...:
Describe what happened here
It disappear!
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...