LKY expands US antimony prospect by 400%

Published 10-OCT-2025 12:19 P.M.

4 min read

Shares Held: 4,754,700

Options Held: 0

Our Investment Locksley Resources (ASX: LKY) has 4x’ed the prospective area at its Desert Antimony Mine (DAM) - next door to $20BN capped MP Materials.

LKY’s Desert Antimony Mine was the sole antimony producer in California’s San Bernardino district during both World War I and II.

The mine was active between 1928 and 1939 and produced between 100 and 1000 tonnes of antimony - producing antimony with grades ranging from 15-20% (and as high as 40%).

We went through a 100 foot mine shaft which follows a rich vein of high-grade antimony:

And here is the old furnace that would have been active back in the day:

It produced antimony with grades generally ranging from 15-20%, although did get as high as 40%.

A big part of what LKY is trying to do is to take DAM back into production (at whatever scale is possible) and produce a 100% domestically sourced antimony product.

Domestic critical minerals supply in the US is a key focus for the US government and overnight we saw China clamp down with more restrictions on rare earths - which adds to the urgency in the USA, (source).

LKY has also confirmed that ore from its Desert Antimony Mine was able to be processed into an antimony concentrate well above marketable specs which are typically >55%.

In fact it was even getting close to the theoretical max that antimony concentrates can reach (71.68%).

LKY’s concentrate graded 68.1%.

We covered that news here: LKY produces high grade antimony concentrate in the US

Now, LKY interpretation of the structural setting of its project means LKY has 4x’ed the potential size of the DAM.

We also noticed LKY mention that there is now potential for a new parallel target ~150m to the west - this could mean that when LKY drills the project there is potential for a larger, multi-zone mineralised system.

(Source)

LKY now has a silver target too?

We also noticed LKY ranked silver/base metals target to the east of its DAM.

Rock chips from the target returned up to 216 g/t silver grades, along with anomalous lead, zinc, and copper results.

LKY also said there were multiple prospecting pits and that the 11 priority areas around that part of the project would be followed up with sampling/mapping.

We are silver bulls so anytime we see something silver it immediately catches our attention.

LKY’s project is right near the Nevada/California border and Nevada is home to some of the biggest silver producing mines in the world so we definitely want to see what comes from the mapping work LKY does here.

One of these mines belongs to the ~$20BN capped Couer who operate the Rochester mine which produced ~4.4Moz of silver in 2024 and is the world's largest silver producer.

Rare earths targets ~1.1km to the north of MP Materials?

The final part of today’s announcement was the work done on LKY’s ground that is closest to MP Materials’ Mountain Pass mine.

LKY identified multiple east-west trends on those blocks which LKY thinks could be “indicating deep seated mantle tapping structures highlighting the potential for REE hosting carbonatites”.

That tells us that LKY is seeing the right type of geology at surface, but that its still very early days before claiming these as concrete rare earth targets.

Here is the target area LKY was mapping relative to MP Material’s mine:

(Source)

With the US currently lacking domestic antimony production combined with a reduction of exports from China, LKY’s Mojave Project could play a crucial role in securing a domestic supply of this critical metal.

At the moment there are no domestic producers of antimony concentrates in the USand antimony has key uses in defence systems, semiconductors, and metal alloys.

China, Russia and Thailand are the major producers/processors globally controlling more than 90% of the market.

The expanded scale and early results are positioning the company well to potentially capitalise on US government initiatives aimed at reducing reliance on foreign sources of critical minerals.

Earlier in the week LKY updated on the production of high grade antimony that we covered here.

What’s next for LKY?

Drilling (this quarter) 🔄

LKY expects drilling to start this quarter, with first results expected before the end of this year. (Source)

LKY has received approval for its expanded Plan of Operations (“POO”) to be approved (which is LKY expanding the size of its currently permitted drill program).

Here is where LKY’s initial drilling program is scheduled:

(Source)

With the rare earths drill program, LKY plans to test areas where a number of high grade rock chip samples were found, grading 1.20% to 6.87% TREO (rare earths).

With the antimony drill program, LKY plans to test for the extent of mineralisation near the historical antimony mine.

Secure licence agreement with Rice University 🔄

Now that LKY has signed a partnership agreement with Rice University, the next stage will be to secure a larger licence deal over whatever technology is developed from the R&D agreement.

This will take some time to work out the IP sharing and mutual development of the technology.