Pickaxe
From The Blockheads Wiki
A pickaxe is used to cut stone, sandstone, marble, etc. at a faster rate than bare hands or a spade. It can be made at a tool bench.
The stronger the material a pickaxe is made out of, the faster it works. A steel pickaxe will remove a block of common stone in two strokes.
A pickaxe made of gemstones produce a multiple of the material being harvested.
A pickaxe made of gold will randomly harvest additional items based on the type of block being struck.