caver

A caver was a worker, typically informal or self-employed, who processed the tailings heap or dump of an established mine to recover small fragments of ore that initial extraction had missed or abandoned as uneconomical. The work was purely manual: picking through discarded rock with hammer and chisel, sorting by eye and hand, and selling salvaged material to smelters or ore dealers. Cavers operated on margins so thin that their labour cost had to be nearly zero, making the role one of last resort during economic hardship.

The practice flourished in the 19th and early 20th centuries, particularly in hard-rock mining regions where ore grades were uneven and processing technology was crude. A caver might work alone or in small crews, often without permission from the mine operator, treating the tailings as common ground. Some mines tolerated cavers as a form of free processing; others actively drove them off. The work was seasonal and irregular, spiking when ore prices rose and ore merchants became willing to handle lower-grade material.

Cavers targeted tailings from copper, tin, lead, and precious metal mines. They used gravity separation, breaking larger rocks to access ore veins or disseminated minerals, then washing or panning to concentrate heavier particles. The ore recovered was seldom pure; it went to small smelters or refiners accustomed to handling heterogeneous feed. A successful caver might extract 5 to 15 percent additional material from a heap that the primary operation had written off as barren.

The term declined sharply after mechanised milling became standard and mining companies began logging and valuing tailings more carefully. By the mid-20th century, cavers had largely disappeared from formalised mining landscapes, though the practice persisted in artisanal and small-scale operations in some regions. Modern heap leaching and tailings processing have rendered the caver's slow manual labour obsolete, though the economic logic remains: where waste contains recoverable value and labour is cheap, someone will attempt to extract it.