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When fresh it is tan in color, but when weathered it is brown. Some siderite chunks contain cavities lined with euhedral rhombs of siderite to 2cm in maximum dimension. Quartz, silver, chalcopyrite, sphalerite, cerussite, chamosite and anglesite have all been found within these siderite vugs
Silver - Ag - Silver occurs as thin to stout wires to several mm in length. The silver wires are often branched and coiled into intricate nests. Some specimens have been found where the wires are uncoated with a metallic luster. More often, however, they are tarnished or have a rusty brown growth on the surface. Gold and copper colored wires are likely tarnished silver specimens. The matrix in which the silver is found is that of vuggy siderite with abundant chalcopyrite.
Smithsonite - ZnCO3 - Smithsonite forms as a crust with white to pale green rounded crystals with a frosted outer appearance. It is found usually on the surface of massive sphalerite.
Sharp individual crystals are rare. In one specimen smithsonite crystals have a tapering pinecone shape, in another they show a crude prism with a sharp trigonal termination.
Sphalerite - ZnS - Sphalerite is common in massive form. It is dark brown, nearly black in color with prominent cleavage. Good crystals are sometimes found within the siderite vugs. Single tetrahedra are rare, usually Mascot sphalerite forms as composite crystals.
Crystals of Calcite and Fluorite from the Mascot have been reported by reliable sources. I haven't seen the specimens and don't want to comment on them here. A manganese oxide of undetermined species coats the surface of dump boulders.
There are also a couple of unknowns that may prove interesting. One forms as lemon yellow platy crystal crusts. SEM EDS analysis shows only lead and sulfur. It doesn't look like anglesite and the only other possibility with that chemistry would be Lanarkite or Susannite. Another Mascot unknown forms as sky-blue to greenish flat disks with a pearly luster and a crudely hexagonal form. Analysis shows it to be a copper-zinc carbonate. The rare mineral Claraite is a distant possibility.
The study of the Mascot minerals is not a solitary endeavor on my part. I thank other members of the Mascot team for their help. They include Gene Bearss, Ed Hakesly, Gordon Jackson, Tom Mortimer, Jim Nizamoff, Al Plante, Art Smith, Vince Valade, Scott Whittemore, and Bob and Anna Wilken.
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