Reserves & Resources


The Piedras Verdes mine is being mined in multiple phases.

  • The LOM plan features 14 pit phases of varying sizes. Active pit areas and planned phases merge into one large ultimate pit.
  • The pit sequencing sees the western phases mined to final limits ahead of the eastern phases, creating significant backfill dump space to shorten waste hauls.

Measured and indicated resources consist of copper oxides principally chrysocolla and neotocite/tenorite, copper oxides with native copper and cuprite, chalcocite, mixed oxidechalcocite and chalcopyrite-bornite. The most recent resource model includes a total length of 229,720 m of diamond and reverse circulation drill holes.

Piedras Verdes Pit Phase Solids



Piedras Verdes Ultimate Pit Design



Future of Piedras Verdes


When Invecture Group acquired Cobre del Mayo in 2009, it had less than 1 billion pounds of copper in reserves and a mine life expected to end in 2018. An aggressive exploration program was started in late 2011.

The process of the exploration program started with the core samples from the drilling program divided into two samples. One half remains at Piedras Verdes for control. The other half is delivered to certified assay laboratories. The results are analyzed by geo statisticians and handled by specialized software to create a three dimensional block model. Mining engineers use this model to plan the mine and establish the size, location and nature of future pits, haul roads, waste dumps, ponds and leach pads.

This program has identified over 2.5 billion pounds of reserves that will enable Piedras Verdes to operate through 2031.

Currently, the Cerro Chato trend is being drilled and it is expected to have an updated resource by the end of 2017. There is on-going work so that this resource can be turned into a reserve.

Our objective is to substantially further increase our copper reserves and our mine life, enabling us to continue to operate and contribute to the community for many years to come.