Why is the Humble Cuttlefish in the Jewellery Industry?

The cuttlefish is a relative of the squid. It has one big difference in that is has a bone called the cuttlebone which is made of calcium carbonate and can allow the fish to float and sink at will. You will know the cuttlefish bone as the thing that you buy from pet shops to give your canary or other bird something to sharpen his beak with. But you don't see them as big as the one next to Sparky there!

That backbone is precisely why this fish has been an important part of the jewellery industry.

When a jeweller makes a piece of jewellery he sometimes has to forge the metal and then bend and cut and file just in order to get the correct shape.

Well, if he has something resembling the shape that he wants already then wouldn’t it be great if he could use that as a model and make another one just like it!

That’s where the cuttlefish bone comes into play.

In simple terms you take a piece of bone, slice it into two halves and then press the model into one half stopping about halfway through and then put the other half of the bone on top of that and press them together like a sandwich. You then take out the model, put the two pieces together again and bind them up with wire.

You now have a mould of the shape you want. The next step is to pour molten metal into the mould and when it cools you have a copy of the item.

The reason why cuttlebone works is because it is soft enough to penetrate with the model but hard enough to stand up when you take the model out. Lastly, it is fire resistant and when you pour the metal into it there is no danger of fire.

This process is relatively quick and saves the jeweller a lot of time and wasted metal. It is messy and kind of primitive but is still used today by some jewellers with small workshops.

Author: Gary Hocking who has his own jewellery website http://www.jewelleryexpress.com.au