Occurs in Pinal County. Common in Arizona.
Chemical Formula: FeCO3
Specific Gravity: 3.8-4.0
Hardness: 3.5-4.5
Siderite is an iron carbonate mineral that often appears as yellowish-brown to brown, rhombohedral crystals or masses. It is an important ore of iron.
Next Pinal County mineral: Sillimanite