The member is commonly pyritic , and weathers to a distinctive white colour on inland exposures.
The assemblage present included quartz, chalcopyrite, pyrite , sphalerite, magnetite, and hematite.
In rare examples there is evidence of fracturing of the axis after pyritization .
This is shown by specimens with a fine network of pyritized algae covering the surface of the cavity.
The mordenite is associated with a hemispherical form of pale yellow calcite and cubic pyrite .
Its down-dip sulfide ores were sideritic and pyritic , with golden barite forming one of the gangue minerals.
The mill produced a lead concentrate, a zinc concentrate, and pyritic tailings.
So when we decided to investigate pyritisation with colleagues from Cardiff University we focused on plants.
Molds and pyritic casts are represented in some sandstone beds but are rare.
Chalcopyrite is occasionally found in the manto orebodies as small crystals on sphalerite and pyrite .