There are many ways to set gemstones into rings, pendants and earrings or other pieces. There is claw set, bezel set, half bezel set and there is inlaying.
Normally you get a stone such as a ruby and it might measure 4mm and be an oval shape. It might also be 2.5 mm deep. So you go looking for a setting to fit that stone. You might need to have a setting specially made to suit your desire.
Inlay setting is much different to that. The manufacturing jeweler makes a piece of jewellery to a chosen design. Let’s say it is a ring. He makes the ring entirely even up to the stage of almost the final polish. Then he finds some stones to set in the ring. At this stage, he does not even have to have any stones in mind. He then finds some opal of a special kind.
The very best opal for this purpose is likely to be a good crystal opal. This is opal which is transparent. You can see faint shimmers of colour through it when you hold it to the light, especially sunlight. It looks very ordinary until you put it down on a black background then the magic happens. Brilliant colours burst into life.
Any metal can be used for making inlay jewelry. The settings are made in the form of a hollow or a well in which the opal sits. It can be any shape rectangular, round, triangular or nay other shape imaginable. The depth of the well should be about 2mm. The stone is cut to fit into this well.
This is the way that I cut the stones and others do it differently. First I choose the top face of the stone and I grind it flat. I then put a dop stick on the top of that surface. A dop stick is a piece of wooden stick which has hot wax on it. This is stuck to the opal so that I can hold the opal.
Next I look down into the hole and I then start to cut the opal to the shape. Let’s say it is a rectangle for this exercise. I have two long sides and two short sides. I start to cut each side until I get close to the size. From then on I start to taper the opal sides as I get closer to the shape. This way I get the opal to fit into the shape but if I make an error in judgement I can cut some off the bottom and make the taper wider at the top end so that it fits.
Eventually the stone will fit in the well but it will protrude about one millimetre out of the top. I then mix the glue which will be a super strength Araldite two part epoxy glue. This is a clear glue but I then mix in a tiny drop of black tincture that I get from a paint shop.
I put the stone in the well with this glue. It is a tight fit but as it was tapered to get it inside then there is room for the glue. I make sure the metal is scratched clean and I warm the opal to dry it a little. I then apply mild pressure with a tiny clamp such as a spring loaded clothes peg on the stone and I leave this for 36 hours.
I then come back and I grind the top of the stone flush with the metal. Sometimes I grind the metal a fraction as well. I then polish the stone on a polishing wheel for opals and I hand polish the metal with small wheels and the correct metal polish.
That is a great deal of work and it takes a lot of practice. Sometimes, if I haven’t cut any inlay stones for several weeks then I will cut the first one with a piece of potch or worthless opal. This might take me 30 minutes and is a waste of my time but it is necessary to get my eye in, or get the feel for what I am doing. I find if I cut all day after a few hours I can just pick up a piece and grind it to the approximate size after just a single look at the piece of jewellery. But I lose that ability after about a week.
How strong are inlaid stones?
Well the stone is very well protected as it is sitting down surrounded by metal with a cushion of glue between it and the metal. So I think it is very safe. If the glue is a good one then it will be extremely difficult to get the stone out. I generally need to drill stones out of pieces if I am not happy with the inlay result. If all stones have to come out I can put the jewellery piece in a solvent for a few days and the glue will dissolve and the opal will be unharmed.