text: The techniques observed in all of them are quite similar. Basically they used the thermic alteration or firesetting (Mohen 1992, Craddock 1995, Eiroa et al. 1996, Timberlake 2003). This consists of applying fire to the rock and then pouring water over it: the rapid changes of temperature will cause cracks within the rocks that can be totally broken with the help of mauls and picks. Then the useful masses were selected, crushed and transported to the production centre that could be in the surrounding area (Mitterberg) or far away (Rudna Glava).
  The mines were exploited in extremely efficient and clever ways, according to the technology available (Jovanovic 1980, Craddock 1995, Timberlake 2003). The entire convenient mineral was collected and the abandoned shafts carefully refilled with gangue and rocks (Mohen 1992; 85). For example, at Mount Gabriel, it was estimated that they extracted the astonishing number of  of rock, gangue and ore. The usable amount of copper was 162.85 tonnes and the final smelting finished metal was 146.56 tonnes (Jackson 1980; 24). The entire process was thoroughly described in 1744 by Lewis Morris, Crown Mineral Agent for Cardiganshire, and, incidentally, antiquarian.
  The tools employed are mainly presented in Lewis' observations, but other ones have been recovered in archaeological context:
  *Stone tools: The most frequent find are the stone hammers, normally made of hard rocks accessible to the mine, beach or river pebbles. There is no standardization of these mauls but is common a system of hafting, usually a groove carved in the middle for where a rope was tied to the handle, like the twisted hazel recovered in Copa Hill.
  * Antler and bone tools: Picks and scrapes made of bone and antlers have been found in the majority of the mines.
  * Wood: Evidence of wooden tools are more infrequent. Nevertheless in places like Ai Bunar or Mount Gabriel were recovered shovels and wedges. A rudimentary system of stairs or scaffoldings can be supposed (Mohen 1992).
  * Metal: The use of any metallic tool is rather strange and extraordinary. It seems that the copper was not used for the miners' tools. However copper chisels and discarded axes could be utilized as wedges.
  * Other evidence: The presence of coal and charcoal, crucial for the firing (fire-setting) and furnace (fuel), is habitual. Leather sacks (at Ai Bunar) and shoulder baskets (at Copa Hill) were used to transport the crushed mineral.