Geological Hammer

"A geologist's hammer, rock hammer, rock pick, or geological pick is a hammer used for splitting and breaking rocks. In field geology, they are used to obtain a fresh surface of a rock to determine its composition, bedding orientation, nature, mineralogy, history, and field estimate of rock strength. In fossil and mineral collecting, they are employed to break rocks with the aim of revealing fossils inside. Geologist's hammers are also sometimes used for scale in a photograph. The hammer also serves as an extension of the senses, permitting the geologist to perceive the rock's granularity, soundness, and resistance to fracturing that may be relevant to its use or identification." (Wiki)