Mineralogy of a calc-silicate locality near Genesee Park, Jefferson County, Colorado

The Genesee Park calc-silicate locality yielded large grossular specimens in the 1930s but an interesting suite of smaller specimens may still be found today. The formation of the Precambrian gneiss is discussed, together with the calc-silicate interbeds partly deformed into lenses composed of massive quartz- and calcium-bearing silicates. The mineralogy section discusses the geochemistry and crystal habitat of 13 minerals and provides photographs of grossular, vesuvianite, scheelite, titanite and epidote euhedral specimens. The final section gives advice on collecting mineral specimens at the site today. -M.J.Smith