Setting Antique Cut Stone....

[Mary]

I am trying to find an Antique Cut Punch Block but it seems no one does them anymore does anyone have an idea where I might get one new or old ?

[Dennis]

Hi Mary,

Are you after a collet block? Could you explain in more detail what kind of setting you are going to do? What cut is your stone, and what sort of size? Dennis.

[Mary]

Hi Dennis,

Yes it's a collet block I want, the client wants a rubover setting on a 6mm Antique Cushion cut Aquamarine with a chequerboard cut. Mary

[Mary]

Hi Dennis,

Yes it's a collet block I want, the client wants a rubover setting on a 6mm Antique Cushion cut Aquamarine with a chequerboard cut. Mary

[Dennis]

We are getting there slowly. Is it 6.0mm square with the corners missing, or does it have rounded corners and bulgy sides, or is it triangular with bulgy sides? Also is it faceted, or a cabochon? Cookson have a goodly range of collet blocks, which are for faceted stones and also fancy triblets, which might well be more appropriate and will do for both.
In any case it is far easier to get the shape of the collet nearly right first and then perfect it with a triblet or in a block. But what you are aiming for is quite advanced and not for a beginner.

Jinks McGrath in her book 'The Encyclopedia of Jewellery making techniques', page 124 has some universal diagrams for making tapered bezels.
The advantages of these are that:
1. All you have to do is make them a little too tall and then adjust the height when you see the stone in place.
2. Being tapered the stone can be seated without a bearer.
But they are not suitable for cabochons.

All this is rather hypothetical, but if you can describe the shape of the stone it might be possible to simplify matters for you
May I also mention in passing, that aqua. can be quite valuable and if you break the stone during setting, which can easily happen, you will be responsible for its cost? Dennis.

[Mary]

Hi Dennis,
Thanks for your detailed reply, the stone is facetted, has sharp corners and curved (cushion shaped) sides. I have seen exactly the block I need in the Oppi book from the mid 1960's- but manufacturing is on the decline everywhere and with it goes speciality tools. I guess I am being lazy not wanting to fiddle with making the pattern etc plus there is the cost of the gold to factor in, oh and eye strain!
Mary

[Dennis]

Right Mary,
Assuming now that you have a faceted stone, 6.0 mm square, with sharp corners and slightly convex sides, here are two approaches:

1. Make an oversized, square tapering collet a la Jinks McGrath, using strip cut from 0.3 or 0.4mm 18ct sheet. Perfect it in a normal square collet block and when you have it made insert a round mini-triblet to bow the sides slightly until it fits your stone.

2. Make a straight-sided collet around a square mini-triblet (a cheaper option) and do the same trick to bow the sides. For this one you will also need a bearer, which can be a tube within the outer tube but lower, to support the stone, or it can be a soldered in wire.

There is lots to learn, so I suggest you practice with copper first. We shall all look forward to seeing your result, Dennis.

[Mary]

Thanks for all your help Dennis, Mary

[ps_bond]

The other method I'd look at is to form your collet on a sparrowhawk anvil - starting from the square tapered collet as Dennis suggests. Both the squaring up and bowing of the sides can be done on the same tool.