Pyrite - Tea Cove, Port au Port Peninsula, Newfoundland, Canada

FeS₂

Tea Cove, located on the Port au Port Peninsula in Newfoundland, Canada, is recognized for its remarkable geological diversity and mineral occurrences. Among the notable minerals found in this area is pyrite (commonly known as "fool's gold"), which is prized for its cubic crystal formations and metallic luster.

Pyrite

Description:

• Chemical Formula: ${\text{FeS}}_2$ (Iron disulfide)
• Appearance:
  • Crystal Habit: Typically occurs as cubic or pyritohedral crystals, but also found as massive or granular aggregates.
  • Color: Brassy yellow with a metallic luster, often leading to its nickname, "fool's gold."
  • Hardness: 6–6.5 on the Mohs scale, making it harder than many other sulfides.
  • Streak: Greenish-black to brownish-black.

Occurrence in Tea Cove:

• Geological Setting:
  • Pyrite in Tea Cove is associated with the sedimentary and volcanic sequences of the Humber Zone, part of Newfoundland's Appalachian geological framework.
  • It forms in hydrothermal veins and as a disseminated mineral within host rocks such as shales, sandstones, and volcanic flows.
• Mode of Formation:
  • The pyrite in this locality is believed to have formed during hydrothermal activity, where sulfur and iron-rich fluids interacted with the surrounding rocks.
  • Some occurrences may be linked to diagenetic processes in sedimentary rocks, where pyrite forms as a replacement mineral.

Notable Features:

• Tea Cove pyrite specimens are often well-crystallized, with sharp cubic and occasionally striated faces.
• Some specimens exhibit complex intergrowths or are accompanied by other minerals such as quartz, chalcopyrite, and galena.

Scientific and Collecting Significance

Scientific Importance:

• Pyrite from Tea Cove provides valuable insights into the region’s geological history, particularly in the context of hydrothermal and sedimentary processes.
• The mineral’s occurrence in the Appalachian Orogen offers clues to ancient tectonic and fluid activity.

Collector Appeal:

• Tea Cove pyrite is prized by collectors for its sharp crystal formations and metallic brilliance.
• Its association with other sulfide minerals enhances its desirability for mineralogical collections.

Safety and Handling

• Pyrite can oxidize over time, producing sulfuric acid and iron oxide ("pyrite disease"), especially in humid conditions. Proper storage in a dry, stable environment is essential to preserve specimens.

Conclusion

The pyrite deposits of Tea Cove on the Port au Port Peninsula highlight the rich mineral diversity of Newfoundland's geological landscape. With its distinct crystal formations and scientific relevance, Tea Cove pyrite is a notable contribution to the mineralogical heritage of the region.

Approx. specimen size: 40mm x 35mm x 15mm