[Yoritomo]

Hello!

        I plan to make sealled glass boxes for all my specimens.However,this is not easy.It will be very expensive and it requires the specimen doesn't move inside the box.These specimens are very frafile and they can break easily.Brakage lows the value of the specimen as bad chemical treatment does.

        Btw,I gave it a search on the internet and I found out there are several types of Silica gel.Colorless is non-indicating Silica gel.This is pure Quartz and is harmless.However,they usually mix non-indicating with indicating blue(CoCl2-indicating).It is likely that this cases the light purplish blue color to my beads.They are transparent but they have an internal light coloration which they lose when saturated with water.

        Is CoCl2 an acid? I've read that CoCl2 and CoCl2.6H2O (the hydrated form) are both lewis acids.Is that true?

         Is it possible vapours to be released from the beads?

[billnotgatez]

Is it hard to get very low moisture nitrogen gas?

[Yoritomo]

NItrogen gas?

   I have no idea...I can ask.Why are you asking?

   What about the questions about the Cobalt Chloride?

            I wish to all of you to have very happy New Year Eve!

             -Kostas.

[billnotgatez]

I wish the guys who collect elements would chime in.

In any case I momentarily, caved in to the notion you wanted to store these items in hermetically sealed containers filled with a dry inert gas. Nitrogen is relatively inert, but helium is better. Medical grade is usually free of contaminants to include water. I now think that it might be going overboard.   

http://en.wikipedia.org/wiki/Hermetic_seal

[Yoritomo]

Hello!

        I wish a Happy New Year to everyone!

        Very interesting idea.However,it really depends on the specimen chemical nature and in which grade these elements are inert towards them.

        My main problem now is to undestand if the indicator(whatever it may be-Cobaltous Chloride or something else...) can be desorbed from the Silica Gel beads,whether as anhydrous or hydrate.

        The room temperature is 23 or less and it gets only less than that(when I open the window to refresh the air.).

         In literature for Silica Gel says that it could be regenerated if heated at 150 *C for about 2 hours.The indicating Gel is supposed to turn blue again.(Which means that Cobaltous Chloride is not supposed to be desorbed at this temperature for that period of heating.)

        So,the question is both physical and chemical.

             

           

[Borek]

I seriously doubt cobalt chloride will be able to leave beads even at much higher temperatures. Just don't let the beads directly touch your specimens, that's all you should care about.

[Yoritomo]

Thanks a lot Borek!

         I'll follow your advice!

            Btw,any good book for starters at Inorganic Chemistry?

[Yoritomo]

 Sry,my English is still too bad...I meant a book for beginers.My apologizes!

 

[constant thinker]

How about vacuum sealing? It's really cheap. Easy to do. Gentle.

[Yoritomo]

Well,most say that the best way to protect Sulfides is to store them in a cool dry inert and O2 free enviroment.How could I achive vacuum?Isn't that too difficult?

[billnotgatez]

I do not think you can find an inexpensive enough container to do vacuum storage. That is why I thought of helium. If that was too expensive then dry nitrogen maybe. But, again I think this may be going overboard.

[Yoritomo]

   Expensive is relative...when a specimen costs $10.000,one would like to afford such a case.I don't know how Helium works,but I guess it won't be too expensive.

   I started this topic for my own specimens,no doubt,but I'm also thinking of providing all this info to Sofia Mineral Museum.The curators there are excellent specialists on Mineralology,but their knowledge on storing specimens is limited.They discarded valuable Pyrite (FeS2 -Iron Persulfide) specimens because they started decomposing by oxidation due to Sulfide oxidising bacteria.

    A specimen for a collector means emotional value and money,but for Mineralogy means also scientific value.When a piece is destroied,it's like an archaeological specimen is destroied.Same
is with fossil specimens which are mineralized organisms.

    As you see,this is not going overboard.

          Thank you very very much!
                       -Kostas.
   

[Mitch]

Sulfur reducing bacteria are typically anaerobic respirators so storing in helium or dry nitrogen wouldn't of protected those samples.

[Borek]

IMHO helium will be useless, it will run from containers very fast. Go for dry nitrogen or argon - much cheaper, no problems with gas leaking from containers. Still, it will make sense only for very few specimens.

[billnotgatez]

Drat - where was my brain -- Argon is better than helium