What kind of tool should be used for stemming?

A wooden tamping stick is the appropriate tool for stemming because it is specifically designed to compact the explosive materials safely and effectively. Stemming is the process of filling the upper portion of a blast hole with an inert material to contain the gases created by an explosive charge, which helps in directing the energy of the blast in the desired direction and preventing fly rock. The wooden tamping stick provides the necessary rigidity and non-conductive properties to avoid sparking, which could inadvertently trigger the explosives.

Additionally, wooden materials tend to absorb some vibrations, reducing the risk of accidentally activating any nearby explosives. Properly using a tamping stick ensures that the stemming material is packed tightly, contributing to a more controlled and efficient blasting operation. The other options, such as metal rods, plastic tools, or shovels, do not provide the same level of control and safety, making them less suitable for this specific task in mining operations.