2.5mm diameter stone-grade tungsten carbide pyrite chisel for fossil preparation, to fit the Ammonite. The pyrite chisel is suited to rocks with a very high pyrite content, which it is designed to cut through with ease. 

What is tungsten carbide? Stone-grade tungsten carbide is by far the best material for fossil preparation – it withstands the abrasive nature of rock and stays sharp far longer than other metals like steel which will quickly blunt and wear down to nothing. However, tungsten carbide can be brittle. A stylus can last many years without requiring replacement when looked after correctly.