Cotopaxi

Femont County, Colorado, USA

Found 10/08/2000

Iron (Ungrouped, IAB complex)

Richard and Sharon Walker found a single mass of 243 g while prospecting for gold samples on a forested hillside with a metal detector. The meteorite was buried about 20cm deep in soil under a small tree and the mass was intergrown with the tree roots. Classification and analysis (J. Wasson, UCLA): Metal composition determined by INAA is: Ni = 9.8%, Co = 0.50%, Ga = 48 mm/g, As = 17m g/g, Ir = 1.4 mg/g, Au = 1.7mg/g. The composition is unique compared to all other known meteorites. Cotopaxi is an ungrouped member of the IAB complex.  Type specimens: 21.43 g, UCLA; 20.33 g, Denver Museum of Nature and Science. Main mass (190 g): Denver Museum of Nature and Science DMNS.