Mosaic closes first tranche private placement, preps drill at Golden Island

Montreal, Quebec--(Newsfile Corp. - September 23, 2026) - Mosaic Minerals Corporation (CSE: MOC) ("Mosaic" or the "Company") is pleased to announce the closing of an initial tranche of a private placement of units and flow-through units, as well as the imminent launch of its first drilling campaign on the Golden Island gold project in Abitibi, Quebec.

Private Placement

The Company announces the closing of a first tranche of a private placement comprising 3,526,190 flow-through units ("FT Units") at $0.0105 per FT Unit and 2,609,191 units ("Units") at $0.085 per Unit, for aggregate gross proceeds of $592,031.

Each FT Unit consists of one (1) common share of the Company (each, a "Common Share") to be issued as a "flow-through share" within the meaning of the Income Tax Act (Canada) (each, an "FT Share") and one (1) common share purchase warrant. Each warrant entitles the holder to purchase one Common Share (each, a "Warrant Share") at a price of $0.17 for a period of 12 months from the date of issuance.

Each Unit consists of one (1) common share of the Company (each, a "Common Share") and one (1) common share purchase warrant. Each warrant entitles the holder to purchase one Common Share (each, a "Warrant Share") at a price of $0.12 for a period of 24 months from the date of issuance.

The gross proceeds from the sale of the FT Units will be used by the Company to incur eligible "Canadian exploration expenses" on the Golden Island project that qualify as "flow-through mining expenditures," as such terms are defined in the Income Tax Act (Canada) (the "Eligible Expenditures"), in connection with the Company's projects in Quebec, Canada. All eligible expenditures will be renounced in favor of the subscribers of the FT Units, effective December 31, 2026.

In connection with the offering, the Company paid an 8% cash finder's fee (totaling $20,160) and issued a total of 192,000 finder's warrants (the "Finder's Warrants") to two (2) arm's-length finders. Each Finder's Warrant is exercisable to acquire one additional common share at a price of $0.085 per warrant for a period of 24 months from the date of issuance.

All securities issued in connection with the offering will be subject to a hold period of four (4) months and one day, ending on January 22, 2027. The offering is subject to final approval by the Canadian Securities Exchange (CSE).

Technical Field Work and Drilling Program

As stated in its press release dated August 25, 2026 , the Company has completed a program of technical work and field exploration to prepare for the initial drilling campaign. Key highlights include:

Discovery of new gold-bearing zones in the southwest extension of the main showing.

Recurring presence of visible gold observed in multiple channel samples.

Confirmation of a complex structural network comprising shear veins, extension/tension veins, and stockwork-style networks, hosted within a mineralized granodiorite matrix spanning several tens of meters in width.