If you place a torch(any kind) and drop sand/gravel on it, the sand/gravel does not break .However, if you place a torch ONE BLOCK ABOVE the ground and drop sand/gravel on it, the sand/gravel breaks. And if you place sand/gravel ONE BLOCK ABOVE a torch, the sand does not break
Intended. The torch acts like a block when a sand block is placed above it.
This is also a duplicate of MC-3262