Q: I have two small tusks or teeth which are engraved with pictures of sailing ships. One has the name of a captain on it, and the date 1862-70. What is their value?

Mr T

A. Very hard to say, for the vast majority of these items which turn up around the antiques trade are fakes, replicas made in the past 20 to 30 years.

Originals -- which are called scrimshaws -- are real whale's teeth, engraved by sailors on 19th century whaling ships with knives and needles, and genuine examples can fetch hundreds of pounds each.

The replicas, which are made of resin, look so convincing even experts have been fooled, and are worth very little, usually about £25 each.

If you want to check for authenticity, just heat up a needle and try to push it into the item. A real tooth will be unharmed, but a fake will start to melt!