Kunzite from Afghanistan
Contributed by: Michael Crawford
Date: Oct 13th, 2025
Locality: Dara-e-Pech pegmatite field, Dara-e-Pech District, Kunar, Afghanistan (See on Mindat)
Size: 7 x 13.5 cm
Description:
A large spodumene var. kunzite (LiAlSi2O6) crystal from Dara-e-Pech pegmatite field, Kunar, Afghanistan. This crystal contains a phantom. A phantom is a previous stage of crystal growth where environmental conditions like temperature or mineral content temporarily changed that halted the crystal’s growth and then resumed, trapping the ghost-like outline of the earlier crystal structure. The phantom resembles a smaller version of the surrounding crystal. The crystal is also pleochroic. Shining a flashlight along the c-axis (bottom to top of the crystal) darkens the color of the crystal compared to shining the light at the face of the crystal.
Afghan kunzite is often irradiated to enhance its color. Exposure to UV light bleaches the color. Irradiation can also cause afterglow from exposure to longwave and midwave UV light. This afterglow also disappears from prolonged UV exposure. This specimen has no afterglow.
This kunzite specimen fluoresces different colors under different wavelengths to UV illumination. The fluorescence is orange under longwave light. It is blue under midwave light and pink under shortwave light. The spectrum of the orange longwave emission is a broad peak with a maximum at 594 nm. The orange fluorescence is activated by manganese replacing lithium. The midwave and shortwave spectra have peaks at 432 nm and 430 nm respectively. These peaks are likely activated by oxygen defects in the silica tetrahedra. There is added red in the shortwave emission from manganese activation the combines with the blue emission from oxygen defects to create the pink, fluorescent color.
Summary of luminescence responses:
Spodumene var. Kunzite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Orange
- Fluorescence under Midwave (305nm LED) UV light: Blue
- Fluorescence under Shortwave (255nm LED) UV light: Pink