Sciencemadness Discussion Board

Best way to preserve crystal

Neme - 25-10-2016 at 11:00

As it is written in the tittle, I'm looking for new method to preserve crystals.

I've tried so far:
water glass --> reacted with crystal compound --> failure
spray transparent paint --> not 100% efficient, got blank spaces
nail polish --> heterogenous layer which is not looking good

I need it mainly for mine chrome alum crystals like this one:


IMG_20161025_181317_HDR.jpg - 149kB

yobbo II - 25-10-2016 at 11:41

Something like this?

http://www.ebay.co.uk/itm/OptiCast-100-Water-Clear-Polyureth...

There are cheaper kits if you look

Neme - 25-10-2016 at 11:51

I'd rather keep the shape of the crystal as it is, not a cube with crystal inside, but thank you for tip :)

Dmishin - 25-10-2016 at 12:40

You can grow a layer of more stable, transparent alum over it. I did it with ferric alum (that is also unstable and turns brown in a day), it lives for a year already.

phlogiston - 25-10-2016 at 15:13

I found a solution of "Velpon" glue (a brand) in acetone to be effective in preserving pyritized fossils. It might work well for your application as well.
A publication from our National Cultural Heritage Agency (very knowledgable in the area of preserving a wide range of historically important objects) suggests that wood lacquers (for instance lacquers used for wooden boats) and the above mentioned mixture of "velpon" glue in acetone would also be among the approaches they would consider.
I have no idea (and would be interested to find out) if "Velpon" glue is available in other countries at all, and what is composed of (should the manufacturer ever go out of business).

[Edited on 25-10-2016 by phlogiston]

Neme - 25-10-2016 at 20:54

Quote: Originally posted by Dmishin  
You can grow a layer of more stable, transparent alum over it. I did it with ferric alum (that is also unstable and turns brown in a day), it lives for a year already.


That's actually pretty good idea, did you use potassium aluminium alum or ammonium potassium alum or different one?

Quote: Originally posted by phlogiston  
I found a solution of "Velpon" glue (a brand) in acetone to be effective in preserving pyritized fossils. It might work well for your application as well.
A publication from our National Cultural Heritage Agency (very knowledgable in the area of preserving a wide range of historically important objects) suggests that wood lacquers (for instance lacquers used for wooden boats) and the above mentioned mixture of "velpon" glue in acetone would also be among the approaches they would consider.
I have no idea (and would be interested to find out) if "Velpon" glue is available in other countries at all, and what is composed of (should the manufacturer ever go out of business).

[Edited on 25-10-2016 by phlogiston]


I've never seen it in shop but I can get it from ebay, I'm gonna look at it.

Dmishin - 26-10-2016 at 03:57

Quote: Originally posted by Neme  

That's actually pretty good idea, did you use potassium aluminium alum or ammonium potassium alum or different one?


I used ammonium aluminium alum, to have common ion with ferric alum. By the way, covering ferric alum was not easy because of very large difference in solubility; I ended up making several layers, gradually replacing Fe(3+) with Al(3+). With chrome alum, such complications are not needed.

phlogiston - 12-11-2016 at 17:12

Another interesting material is Paraloid B72. It is a polymer that is used to conserve all kinds of objects, including fossils and crystals. It is not expensive and can be dissolved in several different solvents, including acetone and ethyl acetate.

Neme - 12-11-2016 at 23:30

Quote: Originally posted by phlogiston  
Another interesting material is Paraloid B72. It is a polymer that is used to conserve all kinds of objects, including fossils and crystals. It is not expensive and can be dissolved in several different solvents, including acetone and ethyl acetate.


I've checked it and it looks like a very good way, but it's really expensive...

Sulaiman - 13-11-2016 at 04:31

Since you probably do not need to re-use the crystal ingredients
and want to allow others to handle it - safely
would a clear casting resin be suitable ?
e.g. http://www.ebay.co.uk/itm/Casting-King-SUPACLEAR-water-clear...

(choosing the mould as small as possible saves resin)

Dwarvensilver - 13-11-2016 at 09:52

HI All,

I too have been trying to preserve crystals from absorbing or losing water but not much success yet and have tried the list that Neme has posted above. I tried pouring a water clear bar top type resin over Copper sulfate crystals and the darn things are resin phobic, it just ran slowly off leaving a few clear islands of resin. Even when trying to pour several layers in a crystallizing dish ultimately worked but it was not real pretty and some areas of the crystal had what seemed like a really thin layer of air at the crystal interface that was not there before curing which cut down on the viewing pleasure somewhat. Don't know if it will happen with different resin, chemical combinations? Maybe coat with spray or nail polish first?

Encapsulation may work but the only method I have seen so far is to make an open sided box out of plexi, lexan or some such then after curing cut lexan off and polish all the sides. The time involved is substantial tho.


[Edited on 2016-11-13 by Dwarvensilver]
This looks promising :)
https://www.youtube.com/watch?v=-daK0wBEA3E

I will have to try this, I went to the mold website and they have a couple of nice molds, square and round.
http://alamould.com/product/cube-mold-home-decor/





[Edited on 2016-11-13 by Dwarvensilver]