Calcite with Siderite Petalite Specimen #MAD61609

Specimen #MAD61609

The piece is loaded with dozens of sharp

where some of the globules are smooth and glassy

It is a superb miniature Colorado Quartz specimen that would make a worthwhile addition to a Quartz collection

Calcite with Siderite Petalite Specimen #MAD61609This locality is a bit obscure but is known to Colorado collectors as it has produced some of the most interesting and easily identifiable Calcites from anywhere in the state. These Calcite crystals occur in septarian nodules found in the Mancos shale formation. As far as I know there are only three reported minerals from the locality all carbonates, i. e., Calcite, Siderite and Dolomite. In the early 1980s, my father collected several superb