mounting a closed back gemstone

[georgewes]

I am going to mount a gemstone on a jewelry piece but there will be no open to the back of the gemstone for light to get in. Therefore I would like to put something on the back of the gemstone(or jewelry piece) so it will reflect the sparkle and shine of the gemstone. Any ideas? This question must of come up before at some time since there are plenty of mounted gemstones that aren't open to the back.

[Dennis]

If it is a faceted stone, then there is no need to worry, because even if set in a closed tube it will still sparkle.

If it is a translucent cabochon, then brightening the metal behind (with say a pencil glass brush) will help and any texture would show through too.

In both cases cutting scallops in the edges of the tube or bezel with a burr would let in more light from the sides and also make setting easier.

Pictures: Faceted green tourmaline with closed back and Pink tourmaline with texture behind.

[Snorkmaiden]

This might be frowned on but I cut out a small piece of metallic silver looking cellophane and stuck it behind a rather transparent cab. Was worried the inside would oxidise over time. Don't tell anyone though.

[LydiaNiz]

Hello,
Is it a piece where you can choose the gemstone as your stone choice will help a lot? Is it a cab or faceted stone? As Dennis says, with the former keeping the inside of the setting as bright as possible helps a lot. I pretty much never use an open back with a cabochon, and textures can look great if the cab is very translucent

[theresa]

I saw someone use thin aluminium foil once.

[MMM Jewellery]

The usual "proper" way to do this is with a thin foil of platinum which won't oxidise. A thin foil of fine silver will also work to a point and be a bit cheaper/more accessible. Both of these would maintain the fine jewellery tag for your work, and can be textured etc. If that is not important then the suggestions above such as mirror cellophane etc would work well.

[Anna]

Hi, one other thing comes to mind following from Dennis and Lydia's comment, the depth of colour of the gemstone and to a lesser degree the size may influence how well the it sparkles - specifically in a tube setting. Darker gemstones may not have as much sparkle even if you have polished the inside. I've a few examples from my "box of shame". The stones are relatively small ranging from 3mm to 6 mm. The darkest stone is a garnet and the sparkliest is a white cz, the other two are pale aquamarine and amethyst. It gives a general idea of what round stones in a tube setting might look like. 10255

[georgewes]

Snorkmaiden: Perhaps if you would paint a good layer of cement over the 'metallic silver looking cellophane' it would keep the oxygen out so it wouldn't oxidize over time. Just an idea. I don't really know if oxygen could get in slowly or what but it seems that it would help.

[georgewes]

It is a faceted stone but I found out with the darker faceted stones it is more important to have light coming in the back than a lighter faceted stone. The problem is some of the darker stones that I want to use are the most beautiful.(at least in my opinion)

[Dennis]

In that case why not make a simple basket setting, or buy a ready made?

http://etsymetal.blogspot.co.uk/2010/07/how-to-make-simple-wire-claw-prong.html

[Snorkmaiden]

Snorkmaiden: Perhaps if you would paint a good layer of cement over the 'metallic silver looking cellophane' it would keep the oxygen out so it wouldn't oxidize over time. Just an idea. I don't really know if oxygen could get in slowly or what but it seems that it would help.

It did the job without cement. Still looks good. Like the idea of using platinum foil though. Hadn't thought of that.

10256

[Dennis]

Snorkmaiden: Perhaps if you would paint a good layer of cement over the 'metallic silver looking cellophane' it would keep the oxygen out so it wouldn't oxidize over time. Just an idea. I don't really know if oxygen could get in slowly or what but it seems that it would help.

It's a common misapprehension that tarnishing of silver is caused by oxygen, to the point that darkening silver for effect has come to be called oxidation.

In fact the main pollutant responsible is hydrogen sulphide, either in the air or for instance from foods, such as eggs and onions.

Once a stone has been securely set it takes many years for the background to darken.

So I do wonder whether money is better spent on a higher quality stone, rather than an expensive foil background.

[Snorkmaiden]

Hardly ever set cabs, but you are right about the pollutant Dennis. All my jewellery in Salford tarnishes almost overnight. Fine elsewhere. Also some wearers seem to make things tarnish quickly.

[georgewes]

where can a person purchase platinum foil?