Decision comes after the companies received Wednesday a preliminary geological assessment of the property, which shows Heritage contains several targets for modern alluvial diamond placer deposits.
The Rajo Inca project would convert the existing asset, which has been in operation since 1959 and is due to run out of ore in 2021, to an open pit mine from an underground one.
CEO Fabio Schvartsman said the company would only invest further in nickel if global prices for the metal rise from $13,000 per tonne currently to around $20,000 per tonne.
Researchers from Curtin University discovered reidite, one of the rarest minerals on Earth buried deep within an ancient meteorite crater in Western Australia.