Siderite on GalenaFrom the collection of well known Colorado mineral collector, George Robertson. My dad traded this piece from George in the early 1980s. The piece features dozens of rosettes of tan Siderite which are sitting atop rather lustrous, well formed, cuboctahedra of Galena on Sphalerite and Pyrite matrix. The Julia Fisk Mine is one of the more notable specimen producing mines in the Leadville District, especially since it was one of the few Leadville mines

I photographed the Phosphos under the microscope to better show their quality

Kosnar collection

the twins are beautifully intergrown with sharp

which is one of my favorite phenomena in the mineral world

but to the best of my knowledge

Specimen # BOL711B287

or native elements

Specimen # BOL711B133

This splendid piece is a sharp

I like to call them “black beauties”) is the fact that they’re not always terribly aesthetic

This piece is from a find in July of 2007 at the type locality for the species which was originally discovered along the Contacto and San Jose veins in this mine and first described by Sam Gordon and Mark Bandy

people tend to associate Bolivia with Vivianite