FMF - Friends of Minerals Forum, discussion and message board

[bob kerr]

is anyone aware of a technique for recovering the original color in a Moroccan vanadinite specimen? I have a wonderful specimen that was once red and is now quite brown - mainly due to exposure to light(?).

thanks,
bob

[Cesar M. Salvan]

Hi Bob,

Sorry, but the changes in Vanadinite are irreversible. The light exposure induces structural and chemical changes in the vanadinite, leading to the formation of different vanadium species that distort the internal structure of mineral.

[bob kerr]

thanks Cesar - I kinda thought that was the case. there's a good bit of naturally brown vanadinite around which must be brown for a different reason than light

so how do people display these for a long period of time? special lights?

bob

[Colleen Thomson]

I keep all my Red minerals in drawers - the majority are unfortunately, light sensitive. Please don't leave your Vanadinite in sunlight. display for short periods of time, perhaps? Otherwise, if you want to guarantee they will retain their colour, keep them in a drawer.
there have been alot of brown and Tan coloured Vanadinite coming out of Mibladen over the last few years - they are specific to just a handful of pockets that produced a prolific amount, some quite large crystals and relatively affordable.
Vanadinite is rather lovely - enjoy yours.

[Fiebre Verde]

Thanks for the advice Colleen!

Does this apply to rhodo's as well?
Has anyone noticed a color change in any type of rhodo after extended sunlight exposure?
And what about the effect of daylight on the color with non-direct sunlight exposure (in the shade)?

Gérard

[Antonio Alcaide]

I think many of you will find quite useful this topic

FMF hosts a great amount of information. We can look it up easily using its searching tool.

Regards

[bob kerr]

Antonio - yes, I searched and had previously found the thread to which you refer but it did not address if anything can be done to reverse the effects of light "damage" on any species (vanadinite specifically).

the thread you refer to discusses establishing a list of light sensitive species - and although this is complicated enough of a task - maybe a valuable piece of additional info would be if anything can be done to mitigate the effect.

bob .

[Antonio Alcaide]

[Jordi Fabre]

[Jim Robison]

I recall that on MIndat sometime back there was an extensive discussion (maybe several) on light sensitive minerals. In one of the threads there was a compilation of these minerals, including many that are not red. Also some protective measures were listed. Don't have time to find the sites, but a site search on light sensitive minerals should be productive.