Western Australian explorer Aldoro Resources (ASX: ARN) reports a review of rock chip samples from its recently acquired Wyemandoo project has found “exceptionally high” assays over nearly 9km of outcropping strike.
A total of 52 samples from lepidolite (lithium mica) bearing pegmatites returned an average of 5,493 parts per million (0.54%) rubidium with one sample reporting 17,123ppm (1.7%) rubidium.
Aldoro said these results are comparable with the world’s highest JORC-compliant rubidium deposit, Lepidico’s Karibib deposit in Namibia, which is estimated to contain 6.7 million tonnes of ore grading 0.23% rubidium, 0.46% lithium oxide and 320ppm caesium.
The Wyemandoo rocks also produced anomalous assays averaging 0.63% lithium oxide and 146ppm caesium, with over half of the 20 samples analyses around the pegmatite loop structure returning grades greater than 1% lithium oxide (the highest being 2.12% lithium oxide).
Aldoro said the assays unveil a new rubidium bearing lepidolite pegmatite field, which will be a focus of investigation in the coming months.
“The Aldoro board are encouraged to have secured such a large lithium-bearing pegmatite fairway in its entirety, which demonstrates the early hallmarks of being categorised as a tier one critical resources asset given the initial sample results for lithium, caesium and rubidium,” the company said.
Large sampling program about to commence
A larger systematic sampling program is currently being finalised and is expected to commence later this month. It will focus on sampling at 40-metre intervals along the extent of the pegmatite outcropping and will also utilise the x-ray fluorescence (XRF) tool to indicate the occurrence of the rubidium mineralisation for the immediate forward planning of drill hole positions.
Aldoro added that a review into the resource economics of the mineral combination of the pegmatite fairway is “encouraging” since the current price for lithium concentrate containing 6% lithium oxide is roughly around $2,100-2,200 per tonne. The current price for rubidium carbonate is $1.4-1.5 million.
“Hence, if the mineralisation has an average grade of 1% rubidium carbonate, the mineralisation has an in-situ value of approximately $10,000/t, without considering the mining and processing recoveries,” the company said.
The Wyemandoo project is located 80km southeast of Mount Magnet in Western Australia’s Mid West. It covers 9sq km on granted licence E57/1017 and is contiguous with Aldoro’s recently granted tenement E59/2431 on the Narndee-Windimurra Igneous Complex.
The company acquired the Wyemandoo project in July and began planning rock chip and soil sampling and mapping over the Wyemandoo pegmatite swarm to identify prospective zones for drill targeting.