Blue gahnite – 2.02 ct crystal – Kagoro Hills, Kaduna State, Nigeria
512 and 737 nm: Mn
2+640, 647 and 650 nm: Co
2+
Dark-green gahnite – 0.24 ct crystal – Pico Das Almas River, Paramirim Das Crioulas,
Erico Cardoso, Bahia, Brazil
_PicoDasAlmasRiver_ParamirimDasCrioulas_EricoCardoso_Bahia_Brazil.png)
512 nm: Mn
2+655 nm: Co
2+650-750 nm: Cr
3+ 