Hackmanite from Greenland offers the most striking color change (tenebrescence) I have seen from any place in the world. Most sodalite from the Ilimaussaq Complex is colored - either blue, green, gray, yellow, or some shade in between. This piece is what we call “Red Sodalite” because it actually changes color in sunlight to a reddish color. The sodalite fluoresces a bright orange under LW. Initially under SW the fluorescence is also a bright orange. and turns a deeper orange as the tenebrescence sets in (the rusty color is caused by the deepening tenebrescence). The multiple hues on this specimen make it very attractive.
The bright green fluorescence covering the sodalite in areas is unknown, likely uranyl activated but is a white mineral unlike the typical uranyl salts often found in Greenland pieces. The blue fluorescence is unknown; this is one of the first pieces I’ve found like this. Could be chkalovite but I’m not ready to state that.
Upon exposure to LW UV (or sunlight - clouds best) the sodalite changes color to a pale reddish color (stronger LW, such as the Convoy LED, deepens this color dramatically. Upon exposure to SW UV the sodalite on this piece changes color to a deep purple - in seconds! Expose it to a bright white light (UV free halogen or LED spotlight held directly on the rock) and it reverts back to its natural color almost immediately - unlike the hackmanite from Afghanistan which can take days to revert back to its normal color, this piece changes back in seconds, over and over. The animation below shows the color change (tenebrescence) after exposure to shortwave UV. Read more about tenebrescence at the end of this listing.
