Re: [meteorite-list] blue crystals as desiccants

Here in Germany the dessicants with the cobalt-indicator is more and more replaced by the orange dessicants, as the cobalt-stuff was rated in 2000 to be weakly carcinogenic. I read, that the orange stuff uses that as indicator: http://en.wikipedia.org/wiki/Phenolphthalein Martin

Re: [meteorite-list] blue crystals as desiccants

Hi Zelimir and list, Many thanks for your well written information on desiccants and taking the time to share with all of us. While I didn't know the reasons chemically behind the crystals, I did know from experience that the crystals weren't detrimental from using them with specimens I keep.

Re: [meteorite-list] blue crystals as desiccants

Hi, one basic question: which is the best way to bake-out the desiccant when it's exhausted? Is the procedure the same for the blue crystals and the impregnating silica gel beads? Thanks, Giovanni -- Passa a Infostrada. ADSL e Telefono senza

Re: [meteorite-list] blue crystals as desiccants

Hi Zelimir and list, Many thanks for your well written information on desiccants and taking the time to share with all of us. While I didn't know the reasons chemically behind the crystals, I did know from experience that the crystals weren't detrimental from using them with specimens I keep.

[meteorite-list] blue crystals as desiccants

Hi Al, list, The blue crystals are indeed a cobalt chloride. Most of the current colored (blue) dessicants actually consist in impregnating silica gel beads (balls etc), by dehydrated cobalt chloride, that is blue. For those who worry about the chemistry involved, let me ensure you that

Re: [meteorite-list] blue crystals as desiccants

Hi Zelimir Thanks for the fascinating explanation about how the chemistry of cobalt chloride works. You actually made me say something I thought I would never sayI'm really glad I took college chemistry. Of course that was 25 years ago and I was kind of foolish then. -- Mike -- Mike Jensen