Peter Megaw Talk for the Tucson Gem & Fine Mineral Show 2025

Peter Megaw’s talk, “Santa Eulalia,” will explore the fascinating history, geology, and mineralogical significance of the Santa Eulalia Mining District in central Chihuahua, Mexico.

This district, active since 1703, is one of Mexico’s most important producers of silver, lead, and zinc, yielding over half a billion troy ounces of silver and nearly six million tonnes of base metals. Known for its rich carbonate replacement deposits, Santa Eulalia exemplifies a region where multi-stage mineralization and deep oxidation create exceptional conditions for specimen formation. It has produced some of the world’s finest mineral specimens, including smithsonite, rhodochrosite, and mimetite.

The district is divided into West, Middle, and East Camps, each showcasing unique mineralization styles. Early mining efforts targeted high-grade oxidized ores near the surface, while modern mining has focused on deeper sulfide ores.

Santa Eulalia remains a prolific source of collector-grade minerals, with approximately 200 species identified. Though large-scale specimen recovery has declined, notable discoveries continue, ensuring its legacy as one of Mexico’s premier mineralogical treasures.

Host or Publisher The Tucson Fine Mineral Gallery