Geologist's hammer
From Wikipedia, the free encyclopedia
A geologist's hammer is a hammer used for geological purposes. In field geology, they are used to obtain a fresh surface of a rock in order to determine its composition, nature, mineralogy and history. In fossil hunting, they are employed to break rocks with the aim of discovering fossils inside.
Most commonly the tool consists of a combination of a flat head, with either a chisel or a pick head at the other end.
- A chisel head (illustrated) is useful for clearing covering vegetation from exposures and is sometimes (though inadvisedly) used to pry open fissures.
- A pick head - which terminates in a sharp point to deliver maximum pressure - is often preferred by 'hard rock' geologists who find it useful for exposing minerals. A hammer bearing a pick end is often referred to as a 'rock pick' or 'geological pick' instead of hammer.
- The flat head is used to deliver a blow to a rock with the intention of splitting it, and is thus always present on larger tools - smaller hammers sometimes opting to principally use a chisel end to maximize the impact of a precisely made blow.
The effective power of a rock hammer is mainly considered to be a reflection of its head weight, which may range from 8 oz (225 g) or even less on a small hammer - such as would generally be used for casual use or by children - to 24 oz (900 g) and even more. 16 oz (450 g) is often quoted as sufficient for all rock types although metamorphic or igneous field geologists often prefer weightier tools.
The best geological hammers are forged from one piece of hardened steel, which renders them sturdy and long lasting. Alternatives such as tubular and wooden shafted hammers are more commonly used, in part due to their low cost - a solid shaft may raise the price by 50%.
The form and weighting of the shaft defines the balance, which itself defines the ease, efficiency and comfort of use.
