"I-7 Spodumene 210B-Afganistan. LiAlSi2O6: Spodumene is a characteristic mineral of lithium-rich granite pegmatites. It usually does not have a wide range of composition, but this sample contains enough ferrous iron to provide the broad weak band near 1.0µ and the fall off to the blue in the visible. In addition, water bands at 1.4µ and 1.9µ are evident, and the quite sharp feature near 2.2µ is a combination band of the OH stretching mode. These bands are due to a surprising small amount of clay mineral deposited in microfractures in the spodumene."