This method gives an almost perpendicular end with a relatively rustic/raw appearance, which is especially well-suited for our slate wall brick, Minera RAW. It is unique to Oppdal slate that it can be split this way, and this feature is particularly useful where the edge is visible, such as at the corner of a wall.
You will need:
Place something under the short end of the slate brick to create tension, making it easier to split where you place the chisel.
Ensure the slate brick remains stable.
Strike the set chisel with a few short, precise blows until the slate brick splits.