Lithium-boron supplier ioneer Ltd. estimated a maiden ore reserve at its Rhyolite Ridge lithium-boron project in Nevada of 15.8 million tonnes at 1,900 parts per million lithium and 12,200 ppm boron, using a 1,050 ppm lithium and 0.5% boron cut-off.

The reserve contains the equivalent of 160,000 tonnes of lithium carbonate and 1.1 million tonnes of boric acid, according to the Dec. 21 release.

The project's indicated mineral resource, inclusive of the ore reserve, comprises 950,000 tonnes of lithium carbonate and 7.5 million tonnes of boric acid.

A definitive feasibility study for Rhyolite Ridge is underway and is scheduled to complete in the third quarter of 2019, which will include an upgrade of mineral resources and ore reserves.