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What is Metal Clay?

Fine (.999) Silver Clay

Pure silver is reclaimed from medical, scientific and communications equipment and ground into a fine powder and combined with an organic binder and water to make it malleable.

Metal clay is worked in a wet and dry state and cut, textured, moulded, sculpted or carved in a method similar to ceramics. Once dry and refined it is fired at a high temperature in a kiln. The binders burn off and leave pure silver, a process described as sintering. The texture and shape of the orginal design are preserved intact.

These properties enable silver clay to be made into unique and varied designs. Silver metal clay is .999 pure and is called Fine Silver when finished. It contains no other metals, it is tarnish resistant and due to its purity is less likely to interact badly with the skin.


By comparison, Sterling silver that most jewellery is made with contains 92.5% pure silver and 7.5% copper. The addition of copper gives the metal durability and strength but is also the reason why sterling silver tarnishes with exposure to air and skin.

Sterling silver clays are available (.925, .950 and .960) and due to their finished strength when fired are excellent for making rings or any item that will receive harder wear.

Other Metals

I also work in base metals such as copper and bronze. These are very hard when fired, come in amazing shades and do not require hallmarking. Base metal clays are very cost effective when making larger scale bold pieces.

There is no Nickel whatsoever in any of my work.


Hallmarking is an independent system of quality assurance which tests the metals submitted for purity or the presence of metal alloys. This is a scientific process known as Assaying. Once the type of metal has been determined it is stamped with the Hallmark.

All of Slieve Croob’s silver weighing more than 7.78 grams is hallmarked on the back of the pieces.

Slieve Croob Silver is assayed at the Assay Office in Birmingham. The hallmark contains the following symbols 999 for Fine Silver (most of my work) and 925 sterling silver for rings.

The symbol for Birmingham is an Anchor

My sponsor’s mark is an oval shape containing the letters S C S.