Nevada Lithium Announces Significant Amounts of Critical Minerals Rubidium and Cesium Within its Bonnie Claire Lithium Project
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Nevada Lithium Announces Significant Amounts of
Critical Minerals Rubidium and Cesium Within its
Bonnie Claire Lithium Project
Vancouver, British Columbia – September 17, 2025 – Nevada Lithium Resources Inc. (TSXV: NVLH; OTCQB: NVLHF; FSE:
87K) (“ Nevada Lithium ” or the “ Company”) is pleased to announce significant rubidium (Rb) and cesium (Cs)
mineralization has been identified within existing drill core on its 100% owned Bonnie Claire lithium project (the
“Project” or “Bonnie Claire”), located in Nye County, Nevada. Initial test work indicates these elements have advanced
through the initial lithium/boron recovery stages of the Project’s Preliminary Economic Assessment (“PEA”) flow sheet
and are present in the Pregnant Leach Solution (“PLS”).
Nevada Lithium’s CEO, Stephen Rentschler, comments:
“We are pleased to announce that examination of drill assays from our 2023 and 2024 drilling
program indicate the presence of rubidium and cesium, which are included in the US
Department of the Interior Draft 2025 Critical Minerals List. These elements represent the
potential to increase the significant boron by-product revenue stream identified in our recently
released PEA.
Initial analysis of the Project’s Pregnant Leach Solution indicates that rubidium and cesium are
available for recovery, and the Company is exploring various options to determine the
economics of recovery. Bonnie Claire’s 61 year mine life and processing rate of almost 3 mm
tonnes of ore annually suggest the Project could make a substantial contribution to the US
domestic supply of critical minerals.
The presence of rubidium and cesium at Bonnie Claire is an exciting development that has the
potential to increase the robust economics demonstrated by our PEA, which was announced to
the market on August 6, 2025. We remain focused on creating shareholder value with the next
steps in the development of this asset, located in one of the world’s premier mining jurisdictions,
Nevada, USA.”
Highlights
• A review of assays from four holes drilled in 2023 & 2024 confirm the presence of significant cesium (Cs) and
rubidium (Rb) mineralization in the Lower Zone at Bonnie Claire.
• Significant Cs mineralization present in all holes, including 248ppm Cs over 318.5ft (BC-2401C).
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• Significant Rb mineralization present in all holes, including 313ppm Rb over 298.5ft (BC 2401C).
• Cesium and rubidium grades both display a strong positive correlation with lithium and boron grades.
• Significant cesium and rubidium concentrations were found in the Pregnant Leach Solution produced to
validate the current flowsheet.
Drill Composites
Bonnie Claire displays a s two mineral deposits within the shallowly -dipping strata that underlies the property; 1) an
Upper Zone, from surface to 130m characterised by moderate -grade lithium and boron, and 2) a Lower Zone that is
characterised by high grade lithium and boron.
The Company reviewed all core samples from its 2023 and 2024 drill programmes, which targeted the Lower Zone. In
all holes, the top 10% of cesium and rubidium assays are hosted in the claystones of the lower part of the Lower Zone,
from approximately 2100 to 2700 ft. This lower part of the Lower Zone also displays the highest grades of both lithium
and boron.
Composites for cesium and rubidium are outlined below in Table 1 and Table 2.
Table 1 Cesium Composite
From (ft) To (ft) Interval (ft) Cs (ppm) Li (ppm) B (ppm)
BC-2301C 2040 2400 360 208.7 3,913.9 15,541.1
BC-2303C 2160 2500 340 212.7 4,743.5 16,849.4
BC-2401C 2347 2665.5 318.5 248.0 5,382.3 18,178.1
BC-2402C 2187 2507 320 214.0 3,968.4 17,175.0
Table 2 Rubidium Composites
From (ft) To(ft) Interval (ft) Rb (ppm) Li (ppm) B (ppm)
BC-2301C 1960 2360 400 276.9 4,116.0 15,840.0
BC-2303C 2120 2480 360 284.2 4,688.3 16,441.1
BC-2401C 2367 2665.5 298.5 313.2 5,444.2 18,320.1
BC-2402C 2127 2447 320 293.6 4,285.3 17,625.0
Correlation with Lithium and Boron
The Company has also reviewed the relationship of cesium and rubidium with lithium and boron. Scatterplots of
assays for the same four holes (BC-2301C, BC-2303C, BC-2401C & BC-2402C) have been created and are displayed
below. Cesium and rubidium grades display a good correlation with lithium, with an R2 a little over 0.81.
Such a correlation between lithium, cesium and rubidium and has been identified in illite -bearing samples at the
Thacker Pass deposit, as referenced in the work of Benson et. al, (2023)*.
Cesium and rubidium grades also display positive correlation with boron grades , with an R2 just under 0.8 and 0.69
respectively. The correlation is affected by a low B population (<500ppm B) subset that shows no correlation.
Figure 1 Scatterplot of Cesium (ppm) Against Lithium (ppm)
from BC-2301C, BC-2303C, BC-2401C & BC-2402C
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Figure 2 Scatterplot of Rubidium (ppm) Against Lithium (ppm)
from BC-2301C, BC-2303C, BC-2401C & BC-2402C
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Figure 3 Scatterplot of Cesium (ppm) Against Boron (ppm)
from BC-2301C, BC-2303C, BC-2401C & BC-2402C
Figure 4 Scatterplot of Rubidium (ppm) Against Boron (ppm)
from BC-2301C, BC-2303C, BC-2401C & BC-2402C
* Benson, T, Coble, M & Dilles, J. (2023). Hydrothermal enrichment of lithium in intracaldera illite-bearing claystones, Science Advances 9, eadh8183, 10pp
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Pregnant Leach Solution Analysis
In tandem with this reassessment of the two critical elements, the Company has started to evaluate the PLS produced
by the recent metallurgical program for the presence of rubidium and cesium. Preliminary analysis of the PLS indicates
levels of Rubidium and Cesium high enough to warrant further testing. The Company will investigate
recovery/enrichment options alongside the Lithium flowsheet optimization.
About Cesium and Rubidium
Cesium and rubidium are used across a wide range of specialist uses including atomic clocks, cancer therapy,
photoelectric cells, special ty glasses, and drilling fluids. Current cesium & Rubidium sources include the minerals
pollucite & lepidolite, found in zoned pegmatites, along with potassium -bearing minerals and brines.
Quality Assurance / Quality Control (QAQC)
A quality assurance / quality control protocol following industry best practice was incorporated into the drill program
by Nevada Lithium. Drilling was conducted by Major Drilling Group International Inc. (“Major Drilling ”). Core was
transported by Major Drilling from the collar location and received by Nevada Lithium staff at the Company storage
facility in Beatty, NV. The facility is only accessible to Nevada Lithium staff and remains otherwise locked.
Received core was logged and cut at the facility by Nevada Lithium staff. Logging and sampling included the systematic
insertion of blanks, duplicates and certified reference material (“ CRM”) MEG Li.10.12 and OREAS 750 into sample
batches at an insertion rate of approximately 10%.
All core samples collected were transported by Company staff to ALS USA Inc.’s laboratory in Reno, NV. for sample
preparation. Sample preparation comprises initial weighing (Code WEI -21), crushing QC Test (CRU-QC), pulverizing QC
Test (PUL-QC), fine crushing at 70% <2mm (CRU -31), sample split using Boyd Rotary splitter ((SPL -22Y), pulverizing up
to 250g 85% <75 µm (PUL-31), crush entire sample (CRU-21), Pulp Login LOG-24) and a crusher wash (final crusher wash
between samples (WSH-21)).
Samples were shipped to ALS USA Inc.’s Vancouver laboratory in Burnaby, British Columbia, where the samples were
analyzed using 48 -element four -acid ICP -MS (ME -MS61) and B/Li N₂O₂ Fusion – ICP-AES high -grade (ME -ICP82b)
procedures.
About Nevada Lithium Resources Inc.
Nevada Lithium Resources Inc. is a mineral exploration and development company focused on shareholder value
creation through its core asset, the Bonnie Claire Lithium Project, located in Nye County, Nevada, where it holds a 100%
interest.
The Company recently filed a PEA on the Bonnie Claire Property. The PEA has an effective date of March 31, 2025 and
presents a $6.829 billion after -tax net present value at an 8% discount rate, based on $24,000/tonne Li 2CO3,
$950/tonne boric acid, together with a 32.3% after-tax internal rate of return . Results of the PEA were announced in
the Company’s news release, dated August 6, 2025.
For further information on Nevada Lithium and to subscribe for updates about Nevada Lithium, please visit its website
at: https://nevadalithium.com/
QP Disclosure
The technical information in the above disclosure has been reviewed and approved by the designated Qualified Person
under National Instrument 43 -101 – Standards of Disclosure in Mineral Projects (“NI 43-101”), Dr. Jeff Wilson, PhD,
FGC, P.Geo, Vice President of Exploration for Nevada Lithium and is not independent of the Company as defined by
Section 1.5 of NI 43-101.
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On behalf of the Board of Directors of Nevada Lithium Resources Inc.
“Stephen Rentschler”
Stephen Rentschler, CEO
For further information, please contact:
Nevada Lithium Resources Inc.
Stephen Rentschler
CEO and Director
Phone: (647) 254-9795
E-mail: [email protected]
Media Inquiries
E-mail: [email protected]
Find Nevada Lithium on Twitter and LinkedIn
The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this news release. TSX Venture Exchan ge has not approved or
disapproved of the contents of this news release.
Cautionary Note Regarding Forward-Looking Statements
This news release contains forward -looking statements and forward-looking information (collectively, “forward-looking statements”) within the meaning of
applicable Canadian securities legislation. These statements relate to matters that identify future events or future performance. Often, but not always, forward
looking information can be identified by words such as “could”, “pro forma”, “plans”, “expects”, “may”, “will”, “should”, “bu dget”, “scheduled”, “estimates”,
“forecasts”, “intends”, “anticipates”, “believes”, “potential” or variations of such words including negative variations thereof, and phrases that refer to certain
actions, events or results that may, could, would, might or will occur or be taken or achieved.
The forward-looking statements contained herein include, but are not limited to, statements regarding: the potential for rubidium and ces ium recovery to
increase boron by-product revenue streams; the economics of rubidium and cesium recovery; the potential contribution of the Project to US domestic supply of
critical minerals based on the 61 year mine life and processing rate of almost 3 million tonnes of ore annually; the potential to increase the robust economics
demonstrated by the PEA; exploration of va rious options to determine the economics of recovery for rubidium and cesium; future investigation of
recovery/enrichment options alongside lithium flowsheet optimization; the presence of rubidium and cesium having the potential to enhance project value; and
continued focus on creating shareholder value through development of the Bonnie Claire asset.
In making the forward looking statements in this news release, Nevada Lithium has applied several material assumptions, inclu ding without limitation: the
successful recovery of rubidium and cesium from the Pregnant Leach Solution; the correlation between lithium, boron, rubidium and cesium grades continuing
as indicated by initial drilling results; the availability of economically viable recovery methods for rubidium and cesium; sustained market demand and favorable
commodity prices for critical minerals in cluding rubidium and cesium; the receipt of any necessary permits, licenses and regulatory approvals in connection
with the future development of Bonnie Claire in a timely manner and Nevada Lithium's ability to comply with all applicable re gulations and laws, including
environmental, health and safety laws, supported by political and regulatory stability in Nevada, USA; the availability of fi nancing on suitable terms for the
development, construction and continued operation of Bonnie Claire; the Project containing mineral resources as indicated by drilling results; the reliability of
metallurgical testing and flowsheet development; and the accuracy of geological correlations and grade continuity.
Investors are cautioned that forward -looking statements are not based on historical facts but instead reflect Nevada Lithium's management's expectations,
estimates or projections concerning future results or events based on the opinions, assumptions and es timates of management considered reasonable at the
date the statements are made. Although Nevada Lithium believes that the expectations reflected in such forward -looking statements are reasonable, such
information involves risks and uncertainties, and undu e reliance should not be placed on such information, as unknown or unpredictable factors could have
material adverse effects on future results, performance or achievements expressed or implied by Nevada Lithium. Among the key risk factors that could cause
actual results to differ materially from those projected in the forward-looking statements are the following: fluctuations in commodity prices including lithium,
boron, rubidium, cesium and other critical minerals; uncertainties inherent in mineral resource estimates, including possible variations in ore grade, recovery
rates, or geological continuity; risks associated with the development of recovery processes for rubidium and cesium, including technical difficulties in extraction
and processing; risks associated with the development and operation of mining projects, including operating and technical difficulties, possible failures of plants,
equipment or processes to operate as anticipated, and accidents; regulatory and permitting risks, including delays o r inability to obtain necessary approvals,
permits, consents or authorizations, and changes in laws, regulations and policies affecting mining operations and critical mineral recovery; environmental risks
and liabilities; financing and liquidity risks, inc luding requirements for additional capital; market and economic conditions, including changes in general
economic, business and political conditions and financial markets; competition in the lithium, boron, and critical minerals markets; infrastructure and logistics
challenges; geopolitical risks and changes in government policies affecting critical mineral supply chains; labour disputes and other risks of the mining industry;
currency fluctuations; title disputes or claims; limitations on insurance coverage; timing and possible outcome of pending litigation; risks relating to epidemics
or pandemics such as COVID -19, including the impact of COVID -19 on Nevada Lithium's business; as well as those factors discussed under the heading "Risk
Factors" in Nevada Li thium's latest Management Discussion and Analysis and other filings of Nevada Lithium filed with the Canadian securities auth orities,
copies of which can be found under Nevada Lithium's profile on SEDAR+ at www.sedarplus.ca.
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Should one or more of these risks or uncertainties materialize, or should assumptions underlying the forward-looking statements prove incorrect, actual results
may vary materially from those described herein as intended, planned, anticipated, believed, estimated or expected. Although Nevada Lithium has attempted
to identify important risks, uncertainties and factors which could cause actual results to differ materially, there may be ot hers that cause results not to be as
anticipated, estimated or intended. Nevada Lithium does not intend, and does not assume any obligation, to update this forward -looking information except
as otherwise required by applicable law.