Nevada Lithium Announces Significant Amounts Of Critical Minerals Rubidium And Cesium Within Its Bonnie Claire Lithium Project

(MENAFN- GlobeNewsWire - Nasdaq) VANCOUVER, British Columbia, Sept. 17, 2025 (GLOBE NEWSWIRE) -- 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:

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).

• Significant Rb mineralization present in all holes, including 313ppm Rb over (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 as 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

Figure 2 Scatterplot of Rubidium (ppm) Against Lithium (ppm)
from BC-2301C, BC-2303C, BC-2401C & BC-2402C

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

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, specialty 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 Li2CO3, $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:

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.

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: ...

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The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this news release. TSX Venture Exchange 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”,“budget”,“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 cesium 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 various 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, including 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 including 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 regulations and laws, including environmental, health and safety laws, supported by political and regulatory stability in Nevada, USA; the availability of financing 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 estimates 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 undue 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 or 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, including 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 Lithium's latest Management Discussion and Analysis and other filings of Nevada Lithium filed with the Canadian securities authorities, copies of which can be found under Nevada Lithium's profile on SEDAR+ at .

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 others 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.

Photos accompanying this announcement are available at

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