Geographic location: 

Latitude:  12°31’15.02″ N

Longitude: 107°53’39.32″ E

Administrative location: Duc Lap village, Dak Sor ward, Krongno district, Daknong province.

Sedimentary Pyrite in Duc Lap village
Sedimentary Pyrite in Duc Lap village

Pyrite is formed in the sedimentary environment rich of iron and sulfate. Iron remains as bivalent Fe ion in groundwater (FeO). In the oxygen-rich environment, iron is oxygenated into iron (III) oxide (Fe203). In the insufficient environment of oxygen and rich of depositional sediment (environmental hypoxia), anaerobic bacteria dissolve organic matter and release sulfide compounds (hydrosulfide- H2S). Iron react with sulfide compounds to form pyrite crystals.  – Characteristics: Pyrite crystals distribute evenly on the gray or black gray sediment layer. The crystals are cubic, 0.5-1.5cm in diameter, currently black in color due to the weathered. Many places have been completely weathered, which results in empty cubic holes within argillite.