[Merad]

Are you trying to split it with an axe? You need a sledgehammer and a few splitting wedges. The sledge lets you apply a lot more force than an axe and striking the wedge focuses that force onto a small area. The first wedge will open a crack, then you use additional wedges to expand that crack until she splits.

Source: grew up in a wood burning family, helped split many stubborn hardwood trees (all by hand).