Back to Ganoksin | FAQ | Contact

Anyone ever silvered a gemstone?


#1

Hi

Has anyone ever dared apply silver to a gemstone using Tollens’
Reagent (Victorian era process for silvering mirrors)?

Thanks in advance
Andrew Jonathan Fine


#2
Has anyone ever dared apply silver to a gemstone using Tollens'
Reagent (Victorian era process for silvering mirrors)? 

Thank you, I learned something else today! Way back in qualitative
analysis class, we used that to test for aldehydes.

I remember it because if you leave the test flask uncleaned on the
bench all day, it tends to explode.

Al Balmer
Sun City, AZ


#3

Al,

I understand from my research that the leftover flask should contain
only silver oxide, but also the explosive silver azide. However, the
azide can be deactivated by dilution with water.

I’m still game to try it, but for reasons of safety I really only
want to use small quantities of reagent at a time. What was the
procedure in your class?

Thanks
Andrew


#4

I believe the process is described in some detail, including the
silver azide hazard, in “Amateur Telescope Making” by Albert Ingalls
and others, Scientific American Publications (I think).

Cheers all
Hans Durstling
Moncton, Canada


#5
I understand from my research that the leftover flask should
contain only silver oxide, but also the explosive silver azide.
However, the azide can be deactivated by dilution with water. 

As I remember, left-over solution was mixed with dilute HNO3, but
water was sufficient to make the flask safe.

I'm still game to try it, but for reasons of safety I really only
want to use small quantities of reagent at a time. What was the
procedure in your class? 

Probably pretty standard. The reagent is mixed (strong ammonia and
silver nitrate) just before use, and mixed in the flask with the
suspected reducing sugar, causing the inside of the flask to be
silvered.

One student got to wash out the flask with water and leave it for
display. It turned black within a day or so - chem labs are not a
friendly environment for thin films of silver [g]. The rest of us
used HNO3 to dissolve the silver and clean the flask. There were
details - different sugars and other reducing organics, timing rate
of deposition, stuff like that. It was a long time ago.

Al Balmer
Sun City, AZ


#6

I remember doing this in university, but please DON’T ask me how, as
I have no idea now, after years have passed and I’ve slept a fair few
times since. But I do remember that it was extremely difficult to
get it to work. Very few members of the class managed to make it
work. Not trying to put you off though.

Helen
UK