OTHER KINDS OF GOLD AND SILVER

Alloys are nothing new. Their quality marking or labeling could even be called a landmark in consumer protection, since the hall; of the guild was assurance that customers received what they 1 for. At that time, however, the concern was to keep the precious metals from being diluted too much, since an alloy involves combining metals in their molten form.

Combining two or three sheets or layers of metal, with a layer of base metal under or between precious metals like a sandwich, is another matter. This sandwich analogy is the basis of what is called either rolled or filled gold and silver-and that process was discovered only a little more than two centuries ago by accident.

Thomas Bolsover was a silversmith in Sheffield township in England. While he was mending a crack in a silver knife, he placed a copper coin next to the blade to make the vise tighter. Then he applied heat to the knife to mend the crack, but as he did so the town crier passed by. Distracted by the latest news, he did not notice what he was doing until he looked back at the knife. The copper coin was bonded or fused to the blade. When he experimented with the ruined knife, he found that the silver and copper could be rolled and worked together much as silver alone could be. This discovery led to the making of the Sheffield silverplate that made his town famous the world over and also made silver available to a market that could never before afford it.

In 1817, the method was extended to gold, with karat gold being used with a base of other supporting metal for producing fine jewelry at more economical prices than for karat gold alone. Rolled or filled gold was popular in the nineteenth century, even among those who could afford fine gold, and jewelry of that era commands a good price today.