THE discovery of an £8 million Michelangelo in a forgotten album at Castle Howard will have families across the county digging out those old relics in the attic.

The dusty, forgotten landscape that just might be an Old Master: the china figurine at the back of Grandma's old dresser: those funny coins you dug up in the back garden ten years ago: each of them might, just might, be worth a small fortune.

It's not, admittedly, terribly likely. The popularity of programmes such as Antiques Roadshow means most people are generally pretty much aware if they are likely to have anything that could be of value.

But if you have just inherited your Great Aunt Lucy's home, or if your grandad has given his attic his first spring clean for 50 years, who knows?

So what should you do if you've unearthed a dusty piece of junk that just could turn out to be a valuable antique? Go to the experts for advice, of course.

Who you go to depends on what it is. If it's a painting, your first port of call should be York City Art Gallery. Prepare yourself for a disappointment, though.

Richard Green, senior curator of art, said: "Most inquiries of this kind don't result in a Michelangelo drawing, unfortunately." Still, the gallery does offer a free service to the public for identifying or dating old paintings - and you never know.

"We will be happy to have a look," Richard said. "We will be able to tell you if it is an original, a reproduction, or a print of some kind." They won't, though, give a valuation: for that, you will need to go to an auctioneer or valuation house. There are plenty in Yellow Pages.

If it's a bit of old furniture, your great-great-great-grandmother's bonnet, or even a family album of old photographs, staff at the Castle Museum may be able to help. Again, they offer a free identification service - but won't give a valuation.

Sarah Maultby, assistant curator of social history, said: "We may be able to identify it, say what period it comes from. We could try to look it up in our books, to see if it is similar to anything we have in our collection. The more you know about your own family history and how it was acquired, the more we would be likely to be able to help. But we would not be able to give any kind of valuation."

Finally, if you've dug up some old coins in the back garden, or you're a metal-detector treasure hunter who has found a hoard of silver rings buried up on the Moors, you should approach either your local coroner's office, or your local museum. In York, that would be the Yorkshire Museum. Ask for either Craig Barclay or Cainwen Paynton.

They will be able to advise you if your find is valuable or antique. If it is, it may be declared treasure trove and become the property of the Crown - but at least you'd be compensated.

Useful telephone numbers: York City Art Gallery, 01904 551869; Castle Museum, 01904 613161; Yorkshire museum, 01904 629745. Auctioneers and Valuers are in Yellow Pages.