IRIS now has the right to mine spodumene pegmatites on two properties which form part of its Custer lithium project in South Dakota.

Notably for the company, the approvals granted to its local US partners cover properties which already have a significant history of producing lithium spodumene ore.

This is particularly true for the Beecher Extension property, which represents the southern portion of the Beecher Mine – one of the most prolific past lithium producers in the US.

IRIS Metals (ASX:IR1) is currently in negotiations to acquire patented claims that cover the remaining lithium bearing Beecher pegmatite trend and are private properties that are not subject to the same obligations as BLM claims governed by both Federal and State authorities including the National US Forest Service.

Executive technical director Chris Connell said obtaining the mining licences permitting hard rock lithium extraction was a significant achievement as IRIS was probably the only company in the US to have secured such licences.

“With all the Federal US government grants and subsidies on offer for locally sourced critical minerals, IRIS’ lithium spodumene is expected to be a sought-after product in the US battery market,” he added.

“We currently are in negotiations directed towards securing ownership of patented mining claims to further enhance the scale and economics of lithium mining in the Black Hills of South Dakota.”

The company had first moved into South Dakota in June this year.


Timely lithium mining approvals

The award of the mining licences to the company’s local partner, which is in the process of transferring the permit to IRIS, is timely given the recently invoked Inflation Reduction Act which stipulated that 50% of battery parts and 40% of battery minerals must be sourced domestically or from countries with which the US has a free trade agreement in place.

This is further supported by there being just one producing lithium mine in the US, within the state of Nevada.

IRIS is permitted to fast-track all exploration and mining activities including the right to explore and mine lithium bearing pegmatites at the Black Diamond and Beecher Extended properties.

The Beecher pegmatite trend was mined sporadically between the 1920s and 1950s for lithium, beryllium, tantalum, mica and feldspar with limited amounts of lithium spodumene ore from the Beecher mine shipped to Hill City during the 1940s for processing through a flotation circuit.

While talks are underway to secure the rest of the Beecher trend, the company’s Beecher Extended claim itself hosts a quartz-spodumene pegmatite which is exposed discontinuously for 750m along strike and up to 130m in width.

Meanwhile, Black Diamond is hosted in a north–south trending pegmatite that has predominantly been mined for beryl and feldspar in the past.

While the narrow open cut has focussed on the zone within the pegmatite with the richest beryl and feldspar, the walls on both sides contain logs of spodumene, and mapping conducted by USGS geologist back in 1945 indicate the potential for significant volumes of this spodumene rich zone.

This pegmatite extends north over a 950m strike length with widths up to 60m wide with spodumene mapped over its entire length.


More claims and exploration

The company has continued staking claims over fertile lithium trends in South Dakota.

Exploration is also underway with detailed mapping and rock chip sampling completed while a detailed gridded soil sampling is now underway to identify geochemical signatures and pathfinder elements that vector into known lithium mineralisation.

Trenching, rock saw channel sampling and drill line preparation will commence shortly and drilling is expected to start in December.


This article was developed in collaboration with IRIS Metals, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.