Mosaic Minerals launches exploration at Golden Island

Montreal, Quebec--(Newsfile Corp. - June 16, 2026) - Mosaic Minerals Corporation (CSE: MOC) ("Mosaic" or the "Company ") is pleased to announce the start of its summer exploration campaign on its Golden Island gold property. Field crews are currently deployed on site to begin preliminary work for the season. Preparatory Work and Stripping A team is currently in the field to begin the first phase of the campaign.

Initial work will consist of clearing access roads and cleaning historical trenches. These preparatory steps will allow the Company's geologists to identify priority areas for prospecting and stripping before the arrival of heavy machinery expected in the coming days. Mapping, Sampling, and Exploration As soon as access roads and trenches are cleared, the geological team will conduct an initial surface sampling program, including groove sampling, as well as a complete geological survey.

The campaign, officially scheduled to run from June 16 until the end of July, will include the following steps: Precise Location: GPS survey of all historical trenches, the original shaft, the underground gallery entrance, and the old drill collars drilled by SOQUEM. Underground Evaluation: Safe walkthrough and sampling of the existing gallery to catalog and analyze all internal mineralized structures. Targeted Exploration: Intensive exploration in the immediate vicinity of the main zone.

Link To Map 1 Bulk Sampling Program (Mini-Bulk) To better assess the nature of the mineralization at Golden Island, the Company also plans to collect mini-bulk samples of approximately 500 kg each from the various identified areas. These samples will be processed in a small pilot plant to evaluate the ratio of coarse gold to overall mineralization. This method will act as a large-scale metal screening analysis, thus providing a much more accurate representation of the system's gold content.

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