NK6S8: The iridescent Goethite from Rio Tinto is different from the Tharsis iridescent Goethite, it is not stalactitic and is much more colorful.
From an old find at the classic Rio Tinto mine, this Goethite surprises us with its rich and varied colors.
Cerro Colorado Mine, Rio Tinto Mines, Minas de Riotinto, Comarca Cuenca Minera, Huelva, Andalusia  Spain (±1985)

Specimen size: 11.5 × 8.7 × 5.5 cm = 4.53” × 3.43” × 2.17”