Where is Pyrite in Shale found?
Pyrite (FeS2) in Shale
Got a photo? Identify rocks instantly with the Rockby app
Open the appPyrite in Shale occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Pyrite in Shale
Black Shales worldwide
Common in numerous black shale formations globally, such as the Marcellus Shale (Appalachian Basin, USA), Barnett Shale (Texas, USA), Woodford Shale (Oklahoma, USA), Kimmeridge Clay (UK), and various Paleozoic and Mesozoic shales in Europe, Asia, and Australia.
Coal-bearing sequences
Often found in shales associated with coal seams, indicating similar anoxic depositional conditions.
Deep-sea sediments
Present in anoxic deep-sea sediments and sedimentary rocks formed from them.
Collecting tips
- Look for dark, fine-grained rocks. Pyrite is most commonly found in dark-colored shales, especially black shales, which indicate high organic content and anoxic conditions.
- Examine freshly broken surfaces. Pyrite's metallic luster and brassy color are most evident on fresh breaks. Weathered surfaces may show reddish-brown iron oxides (limonite/goethite) due to pyrite oxidation.
- Check for crystal forms. Look for small, cubic, or irregular brassy-yellow crystals or nodules embedded within the shale matrix.
- Test hardness. Pyrite is harder than shale (Mohs 6-6.5 vs. 2-3), so it will scratch glass and will not be scratched by a steel knife.
- Be aware of 'Fool's Gold'. Pyrite's metallic luster and color can be mistaken for gold, but gold is much softer (Mohs 2.5-3) and leaves a yellow streak, whereas pyrite leaves a greenish-black streak.
Quick Check
- Color:
- Brassy yellow to pale gold (pyrite) in dark gray to black (shale)
- Luster:
- Metallic (pyrite) in dull to earthy (shale)
- Streak:
- Greenish-black (pyrite)
Explore Pyrite in Shale
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.