press release

First Majestic Reports Continued Exploration Success at Santa Elena and Announces Senior Management Update

2025-12-15

TSX - Toronto Stock Exchange · Copper · Molybdenum · Silver · Gold · Zinc · Lead · Germanium · Indium · Sulfur · Nickel · Platinum · Palladium

New drilling significantly expands the gold and silver mineralization of the Santo Niño and Navidad discoveries

Drilling completed at Luna expected to convert substantial amount of Inferred Mineral Resources to Indicated Mineral Resources

Start of scoping-level studies for Navidad and Santo Niño provide guidance on potential mining strategies

Mani Alkhafaji promoted to President & Chief Corporate Development Officer

Vancouver, British Columbia--(Newsfile Corp. - December 15, 2025) - First Majestic Silver Corp. (NYSE: AG) (TSX: AG) (FSE: FMV) (the "Company" or "First Majestic") is pleased to announce the start of preliminary mine planning studies for the Navidad and Santo Niño discoveries located at the Company's Santa Elena Silver/Gold Mine in Sonora, Mexico. Additionally, the Company announces positive exploration drilling results for the Santo Niño and Navidad targets that significantly increase the gold ("Au") and silver ("Ag") mineralization beyond the currently declared 2024 Inferred Resources. Furthermore, drilling in the Luna Zone to the east of the currently producing Ermitaño deposit has successfully infilled portions of the 2024 Inferred Mineral Resources for Santa Elena, and will support the conversion to Indicated Mineral Resource estimates when the Company declares its Mineral Reserves and Mineral Resources for the year-ended December 31, 2025.

Following the encouraging exploration results at Navidad and Santo Niño, the Company is conducting internal scoping-level studies to assess potential underground mining scenarios for the two discoveries. A material handling trade-off study analyzed how to access the Winter-Navidad target and determined that the best access is a straight, approximately 3-kilometre underground ramp with a portal located adjacent to the Santa Elena processing plant. The Santo Niño mineralization presents several promising options for additional access including a potential crosscut from the ramp to Navidad or a new portal situated near the deposit where thick intercepts of high-grade gold and silver are reported within 100 metres ("m") from surface.

Third-party metallurgical testing completed for Santo Niño mineralization indicates that expected metallurgical recoveries for gold and silver are excellent. The testing, conducted during the fall of 2025, was designed to replicate the current mineral processing parameters of the Santa Elena Plant. The results confirm exceptional metallurgical performance, with gold and silver recoveries exceeding 95%, and the mineralization at both Santo Niño and Navidad are compatible with the Santa Elena processing plant.

"The continued success of the exploration program at Santa Elena has prompted the launch of an early-stage scoping level study aimed at defining optimal material handling methods, access to mineralization, mining methods, mining rates, ventilation and dewatering requirements, and ultimately integrating Navidad and Santo Niño to the district's Life of Mine" stated Keith Neumeyer, President & CEO of First Majestic. "As was the case in 2024, we anticipate the 2025 drilling program will translate into significant Inferred Mineral Resource additions for the district. The district continues to demonstrate exceptional potential. In alignment with our organic growth strategy, and partially driven by the increase in available mineralization, the Company has initiated the plant expansion project with the goal of increasing throughput from approximately 3,200 tonnes per day to approximately 3,500 tonnes per day by the end of 2026. This initiative underscores our confidence in the long-term future of the operation."

2025 SANTA ELENA EXPLORATION HIGHLIGHTS

Santo Niño

Drilling at Santo Niño since the discovery announcement in May 2025 has substantially expanded the footprint of gold and silver mineralization. A total of 15,307 m of new drilling was completed over a 32-hole program that has defined extensive mineralization. The gold and silver mineralization identified to date extends greater than 1,100 m by 400 m in strike and dip with the true thickness of mineralization ranging between 2.5 m and 5.0 m. The mineralization remains open to the east.

A maiden Inferred Mineral Resource estimate for Santo Niño is expected to be included in the Company's Annual Information Form for the year ended December 31, 2025, which will be filed at the end of Q1 2026.

Navidad

A total of 10,161 m of drilling has been completed over an 8-hole program in 2025. Drilling at Navidad has returned significant intercepts outside the current Inferred Mineral Resource boundary to the east. Gold and silver mineralization identified to date now extends greater than 1,200 m by 400 m in strike and dip with the true thickness of mineralization averaging between 3.0 m and 4.0 m. The Winter and Navidad mineralization remain open in multiple directions.

Luna

Inferred to Indicated Mineral Resource conversion drilling at the Luna Zone has refined the geologic understanding of the Ermitaño and Aitana veins in the area. Overall assay results and widths are tracking closely to those modelled, with the Company anticipating a high conversion rate. A total of 11,190 m of drilling has been completed over a 33-hole program in 2025.

KEY DRILLING HIGHLIGHTS

Table 1 below presents a selection of drill hole intercepts with significant assay results from drilling at the Santo Niño, Navidad, and Luna targets.

Table 1: Selection of Significant Gold and Silver Drill Hole Intercept Highlights Santo Niño, Navidad, and Luna Targets

DrillholeTarget From

(m) To

(m) True Width

(m) Metal Grades

(g/t) Ag

(g/t) AgEq (g/t)

Santo Niño

SE-25-36Santo Niño Vein180.8187.26.26.30214674

SE-25-37Santo Niño Vein192.5197.13.76.81124619

SE-25-45Vein262.6265.93.15.4259520

SE-25-56Santo Niño Vein359.2364.43.35.82238732

SE-25-39Breccia273.0273.73.65.43273743

Navidad

EWUG-25-078Winter Vein710.5721.88.05.80126554

EWUG-25-052Winter Vein766.0776.97.75.5367291

EWUG-25-078Navidad Vein1045.11054.34.64.8850254

EWUG-25-052Stockwork1165.41176.55.61.354253

Luna

EWUG-25-074Aitana Vein 1205.2213.75.45.04126554

EW-25-397Aitana Vein362.2375.09.12.6367291

EW-25-393Vein392.5405.49.92.3950254

EW-25-399Aitana Vein312.9323.99.63.0454253

EWUG-25-073Aitana Vein 1284.8296.96.11.9657223

DISTRICT EXPLORATION

Exploration across the Santa Elena District continues to yield positive results across multiple targets (Figure 1). During 2025, a total of 64,000 m of exploration drilling were planned and the Company has completed approximately 66,800 m to date, reflecting a decision to increase the targeted metres in a context of exploration success and the Company's overarching growth strategy.

Figure 1: Santa Elena District Map Highlighting Santo Niño, Navidad and Luna Target Areas. Plan View.