Pickaxes are Tools used for mining Rocks. They greatly improve Mining Speed. Like many Tools that are crafted, they can be made from a variety of Materials. Their effectiveness depends on the Material's Work Speed Coefficient. Higher Tier Materials such as Spiritwood (Timber), Darksteel Bar, and Lumina Core Bar greatly improve their effectiveness.
Their effectiveness as a mining Tool is not affected by the final item's Tier or Quality, and as a result do not benefit from Specter Refinement. However, Pickaxes may be used as improvised Weapons, and Specter Refinement does improve their damage.