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 Post subject: Gem silica questions
PostPosted: Mon Dec 04, 2017 9:04 pm 
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Joined: Tue Apr 03, 2007 9:11 pm
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Hi everyone,

I don't post here often but I am a frequent lurker on the forum. I had a few questions about gem silica.

One, I have read a few conflicting sources about the porosity of gem silica. Some sources say that gem silica will become more or less translucent depending on the humidity. I was wondering how true this is as I have found little information about this but the sources that I have located have conflicted each other.

Two, if gem silica will in fact change with the humidity, is the material porous enough to absorb other things like perfumes or skin oils that might affect its appearance later? How stable is gem silica? Will it craze like opal or could it become dehydrated?


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 Post subject: Re: Gem silica questions
PostPosted: Tue Dec 05, 2017 12:01 am 
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Joined: Sun Oct 16, 2005 12:22 pm
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Location: San Francisco
Excellent question.
We know that many varieties of chalcedony are porous enough to be dyed and remain stable for centuries.

Gem silica is usually translucent. At least the most valuable is.
Have you heard that putting opaque gem silica in humid conditions will make it translucent and when it is moved to a more arid environment it goes opaque?

Let's test it.

Or, if anyone has any empirical evidence one way or the other, please share it. :smt112


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 Post subject: Re: Gem silica questions
PostPosted: Tue Dec 05, 2017 12:18 am 
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This os definitely something I have heard repeatedly, both about gem silica and chrysoprase. I have had some cjrysoprase go transparent after a bit of water exposure, and had some Peruvian gem silica go noticeably more opaque after cutting (no overheating involved) though it was only one piece, all the others habe behaved really well.

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 Post subject: Re: Gem silica questions
PostPosted: Tue Dec 12, 2017 12:21 pm 
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I'll try that on a piece I have.
It's a large and flat slice, so should be soaked easily if porous enough.
Will keep you updated.


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 Post subject: Re: Gem silica questions
PostPosted: Thu Dec 14, 2017 8:32 am 
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So :
I have soaked my gem silica piece into water for a whole night.
This morning it was definitely more translucent than yesterday. I could definitely see my fingers through it, and the position of the chrysocolla inclusions on a clear background, while yesterday night it was more opaque and uniform in color.
Let's see how long it will take to dry and come back to its original look.


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 Post subject: Re: Gem silica questions
PostPosted: Thu Dec 14, 2017 8:38 pm 
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Joined: Sun Oct 16, 2005 12:22 pm
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Bravo.


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