This flat contains an extensive selection of characteristic minerals from the Gila River Wilderness in Grant County, New Mexico, collected in 1980 from the Gerd Tremmel collection. The specimens represent a notable variety of zeolites and related minerals from the region, including Analcime, Chabazite, Mesolite and Thomsonite. Many pieces display the locality’s typical white to grey radial, fibrous or botryoidal structures, often contrasting strikingly with the dark basaltic matrix. The assemblage provides an authentic overview of the mineral paragenesis of this important locality in the American Southwest while also preserving its historical collection context.
Geology & Origin
The Gila River Wilderness in southwestern New Mexico is well known for its abundant secondary minerals formed in cavities and fractures of volcanic rocks. Analcime, Chabazite, Mesolite and Thomsonite typically develop there through hydrothermal processes within basaltic and andesitic host rocks. Variations in temperature and pressure produced a variety of crystal habits – from spherical aggregates to radial-fibrous or prismatic forms. This unique flat showcases that mineralogical diversity and offers collectors a historically sourced set from a classic U.S. locality.