Comet Lithium Reports High-Grade Caesium and Lithium Assay Results from Grassroots Pegmatite Discovery at Elmer East Project,
Comet Lithium Reports High-Grade Caesium
and Lithium Assay Results from Grassroots
Pegmatite Discovery at Elmer East Project,
James Bay, Québec
ROUYN-NORANDA, QC
,
Aug. 19, 2025
/CNW/ - Comet Lithium Corporation (TSXV: CLIC) (FSE:
8QY) ("Comet Lithium" or the "Corporation") is pleased to announce assay results from the recently
completed exploration program at its 100%-owned Elmer East Project ("Elmer East" or the
"Property"), located in the Eastmain Greenstone Belt,
James Bay
region, Québec. The program,
conducted from
June 25 to June 30, 2025
, has returned high caesium (Figure 1) and lithium assay
values (Figure 2) from a newly discovered spodumene-bearing pegmatite dyke. Additionally, a trend
to the east of the dyke discovery spanning over six kilometres has returned very good potassium-to-
rubidium ratios (Figure 4), confirming the fertile nature of the system and high prospectivity of the
Property. All 252 assay samples from the initial program have been received.
Follow-up to Spodumene-Bearing Pegmatite Dyke Discovery
As previously disclosed on
July 9, 2025
, Comet Lithium's field team, led by Dahrouge Geological
Consulting, identified a grassroots LCT-type (Lithium–Caesium–Tantalum) pegmatite dyke in the
southwestern portion of the southern claim block. This discovery represents a great outcome given
the program's short duration.
Pegmatite Dyke Characteristics:
Measures between 1–2 metres in width and has been traced for approximately 80 metres in
outcrop.
Remains open to the east, with its western extent pinching out.
Hosts spodumene, along with muscovite and tourmaline, mineralogy consistent with highly
evolved LCT pegmatite systems.
To date, only two grab samples have been collected from the dyke (see table below), both
returning high assay results.
Assay Highlights
Two grab samples from the dyke, located approximately 65 metres apart, have returned outstanding
grades:
Sample ID
Li (ppm)
Li
O (%)
Cs (ppm)
Cs
O (%)
Rb (ppm)
Rb
O (%)
Be (ppm)
Ta (ppm)
Ta
O
(ppm)
E6481203
8,640
1.86
23,100
2.45
3,810
0.42
286
610
745
E6481494
8,760
1.89
13,700
1.45
2,440
0.27
192
691
844
Sample ID
Easting
Northing
Coordinate System
E6481203
370454.55
5811587.09
NAD83-UTM Zone 18 U
E6481494
370393.76
5811607.25
NAD83-UTM Zone 18 U
Flagship Sample E6481203:
Lithium: 8,640 ppm Li → 1.86% Li
O
Caesium: 23,100 ppm Cs → 2.46% Cs
O
Tantalum: 610 ppm Ta → 745 ppm Ta
O
Rubidium: 3,810 ppm Rb → 0.42% Rb
O
Also notable: Gallium (75 ppm)
In addition to high-grade caesium and lithium grades, the dyke also returned highly elevated
tantalum, rubidium and gallium values.
Across the Property, seven samples returned Rubidium values over 1,000 ppm (1,094 ppm Rb
2
O),
with three exceeding 2,000 ppm (2,188 ppm Rb
2
O) (Figure 3). Seven samples returned Gallium
values over 50 ppm, with three exceeding 75 ppm. These geochemical signatures are consistent
with highly evolved LCT-type pegmatites and reinforce the fertile nature of the Elmer East system.
"Discovering such extraordinary caesium and lithium grades at surface, during our first exploration
program at Elmer East, marks a transformational milestone for Comet Lithium," stated
Vincent Metcalfe, Chair and Chief Executive Officer of Comet Lithium. "Caesium grades of this
magnitude are exceptionally rare and represent a strategically important critical mineral, particularly
when combined with significant lithium values. The geochemical signature, with high fractionation
indicators and favourable K/Rb ratios, confirms the fertile nature of the system and underscores the
highly prospective potential of the property, especially around the newly identified dyke. Given that
this discovery was made on the second-to-last day of the program, we are confident that we have
only begun to uncover Elmer East's full potential" added Mr.
Metcalfe
.
Geological Context
The newly discovered dyke lies along a prominent NNE–SSW regional structure, interpreted from
magnetic survey data, within amphibolite crosscut by tonalitic and pegmatitic intrusions. Outcrop
exposure is excellent (~75%), and the dyke remains open along strike, providing strong potential for
additional discoveries.
Geochemically, the pegmatite demonstrates advanced fractionation, as reflected in elevated Cs, Rb,
and Ta contents. Potassium-to-rubidium (K/Rb) ratios remain within a favourable range, consistent
with highly evolved LCT systems capable of hosting both lithium and caesium mineralization of
potential economic significance.
Caesium Market Context
Caesium is one of the rarest critical minerals, with a highly specialized and niche market. To date,
only three deposits globally have ever been commercially mined for caesium: the Tanco mine in
Manitoba, Canada
; the Bikita mine in
Zimbabwe
; and the Sinclair mine in
Western Australia
, which
has since been depleted. Supply today is extremely limited, with Tanco historically being the world's
primary source. Caesium is listed as a critical mineral by the U.S.,
Canada
, and the European Union
due to its scarcity and strategic applications in areas such as advanced electronics, defence and
aerospace, specialty glass, oil and gas drilling fluids, and atomic clocks.
Next Steps
With all assay results now in hand, Comet Lithium will:
Conduct and undertake detailed geological mapping and structural analysis to identify additional
pegmatite dykes.
Plan a targeted follow-up program including trenching and channel sampling.
Prioritize evaluation of strike length, depth continuity, and mineral zonation of the caesium- and
spodumene-bearing dyke.
Figure 1: Elmer East – Map of Caesium Oxide Assay Results (CNW Group/Comet Lithium Corp.)
Figure 2: Elmer East – Map of Lithium Oxide Assay Results (CNW Group/Comet Lithium Corp.)
Figure 3: Elmer East – Map of Rubidium Oxide Assay Results (CNW Group/Comet Lithium Corp.)
Figure 4: Elmer East – Map of K/Rb Ratios (CNW Group/Comet Lithium Corp.)
Cautionary statements
Grab samples are selective by nature and may not be representative of mineralized zones.
QAQC
A Quality Assurance / Quality Control protocol following industry best practices was incorporated
into the sampling program.
All rock samples were collected under the supervision of Comet Lithium and Dahrouge Geological
Consulting employees. All samples were logged and photographed on site while being collected.
Samples were then bagged, and blanks and certified reference materials were inserted at regular
intervals. Groups of samples were placed in large bags, sealed with numbered tags in order to
maintain a chain-of-custody, and shipped to AGAT Laboratories in
Val d'Or
, Québec.
All assays reported were analyzed at AGAT Laboratories in
Mississauga, Ontario
for multi-element
using sodium peroxide fusion and ICP-OES/ICP-MS finishes under AGAT Laboratories code
210378. In the case of overlimit for Caesium (>10,000 ppm), assays were analyzed under package
201-179 using sodium peroxide fusion and ICP-OES finish.
Qualified Person
Vincent Cardin-Tremblay
, P. Geo (ogq #1386, PGO #3347), registered in the Provinces of Québec,
and
Ontario
is Vice President Exploration to Comet Lithium, is a qualified person
under
National
Instrument 43
101
– Standards of Disclosure for Mineral Projects.
He has reviewed the technical
contents of this news release and has approved the disclosure of the technical information contained
herein.
About Dahrouge Geological Consulting Ltd.
Dahrouge Geological Consulting Ltd. Is a global mining and mineral exploration consulting group
providing expertise in professional geological, logistical, and project management services through all
stages of the mining value chain.
Based in
Edmonton, AB
, CAN,
Montreal, QC
, CAN, and
Denver, CO
, USA, Dahrouge and its
predecessor, Halferdahl and Associates, have advised and assisted clients in identifying, exploring,
developing, and optimizing mineral projects and resources since 1971.
About Comet Lithium Corporation
Comet Lithium is a dynamic exploration company with a growing portfolio of highly prospective
assets located in Québec, including several properties in the prolific
James Bay
District. The
Company's land package includes the Liberty Property, located adjacent to Winsome Resources'
Adina lithium discovery, and the Troilus East Property, positioned next to Troilus Gold's gold-copper
project. Comet's strategy is focused on systematic exploration and unlocking the value of its diverse
property portfolio through targeted fieldwork and strategic partnerships.
Forward-Looking Statements
This news release contains statements that may constitute "forward-looking information" within the
meaning of applicable Canadian securities legislation. Forward-looking information may include,
among others, statements regarding the future plans, costs, objectives or performance of Comet
Lithium, or the assumptions underlying any of the foregoing. In this news release, words such as
"may", "would", "could", "will", "likely", "believe", "expect", "anticipate", "intend", "plan", "estimate"
and similar words and the negative form thereof are used to identify forward-looking statements.
Forward-looking statements should not be read as guarantees of future performance or results, and
will not necessarily be accurate indications of whether, or the times at or by which, such future
performance will be achieved. No assurance can be given that any events anticipated by the
forward-looking information will transpire or occur, including if any follow-up exploration programs will
be completed on the Elmer East property, such as conducting and undertaking a detailed geological
mapping and structural analysis to identify additional pegmatite dykes, planning a targeted follow-up
program including trenching and channel sampling and the evaluation of strike length, depth
continuity, and mineral zonation of the caesium- and spodumene-bearing dyke, the timing to conduct
such exploration program and the results of such exploration programs, and if it does so, what
benefits Comet Lithium will derive from any such exploration programs. Forward-looking information
is based on information available at the time and/or management's good-faith belief with respect to
future events and are subject to known or unknown risks, uncertainties, assumptions and other
unpredictable factors, many of which are beyond Comet Lithium's control. These risks, uncertainties
and assumptions include, but are not limited to the risks, uncertainties and assumptions described
under "Financial Instruments" and "Risk and Uncertainties" in Comet Lithium's Annual Report for the
fiscal year ended
December 31, 2024
, a copy of which is available on SEDAR+ at
www.sedarplus.ca
, and could cause actual events or results to differ materially from those projected
in any forward-looking statements. Comet Lithium does not intend, nor does it undertake any
obligation, to update or revise any forward-looking information contained in this news release to
reflect subsequent information, events or circumstances or otherwise, except if required by
applicable laws.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in
the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of
the release.
SOURCE
Comet Lithium Corp.
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For further information:
For further information: Comet Lithium Corporation, Vincent Metcalfe,
Chairman and CEO, [email protected], +1.514.249.9960, 147 Québec Avenue (back
door) Rouyn-Noranda, Québec J9X 6M8, Email: [email protected], Website:
CometLithium.com
CO: Comet Lithium Corp.
CNW 08:52e 19-AUG-25