Is that plate with the golden patina genuine medieval pewter? What is that fussily decorated dull grey teapot with the faux ivory lid knob made of? Pewter? Tarnished nickel-silver? Has the trader missed a trick by pricing it at only pounds 20?
Solutions to the grey-metal mystery are to be found this month when the biggest-ever and probably the finest private collection of British and European pewter comes under the hammer at Phillips, Chester. The 1,500 pieces are expected to fetch a total of over pounds 100,000. American collectors who viewed the collection in New York in June will be among the bidders. And the sale catalogue (pounds 7 by post) will become a collectors' guidebook.
There is not much pewter around these days, whether old or new. But in the three centuries up to 1800 it was the domestic equivalent of stainless steel, or even plastic. Any utensil that did not come into direct contact with a flame - plates, flagons, jugs, pots, candleholders, but not kettles - was likely to be made of pewter.
What little old pewter is left has attracted only a small band of dedicated collectors. It has been a cheap collectable for the past century. You can still buy a pint pewter tankard from around 1810 with maker's "touch mark" (a big blobby hallmark) and the inscription of both the owner and his pub, for the same price as a bright new pewter tankard bought as a birthday present - around pounds 50.
But tin, pewter's main ingredient, is still the fourth most valuable metal (after platinum, gold and silver), and in the old days it was sufficiently valuable for the price of re-casting a battered pewter vessel to be fixed at just a third of its original price.
I visited Hilary Kashden, one of only a handful of pewter dealers, who first showed me a plate with a golden hue - "nature's gilding", she called it - that had spent four centuries in the mud of the Thames. Genuine cast pewter. It was heavy, no doubt about that.
Similar plates in the collection at Phillips, formed by the late Dr Sandy Law, a Stoke-on-Trent GP, are estimated around pounds 500. Dr Law, a former stamp collector, started his collection by stealing a march on the Americans: in a Staffordshire antique shop in the early 1970s, he spotted a consignment of pewter destined for America and bought the lot.
I rubbed the plate's rough surface. "I love pewter", said Mrs Kashden, "because it is not pretentious. It was made by real people for real people. It doesn't masquerade. And it fits in with its surroundings. It looks good displayed with other antiques, especially oak and brass, and with flowers and fruit. Practically anything but silver."
Ah, now that is where the masquerading - and the confusion - comes in. Around 1770 a new kind of pewter was invented, laced with extra antimony, known as Britannia Metal. It was sold highly polished and unashamedly aped silver. Being harder than the old stuff, instead of being cast when molten, it could be made into thin sheets for stamping into moulds, or spun - forced into shape while spinning on a wooden chuck on a lathe.
Britannia Metal wares - including those fussy Victorian teapots and footed sugar bowls - contained less metal and were mass produced at a fraction of the price. They were about a thirtieth of the price of silver. Which is how the new Victorian middle class was able to afford its bits of posh for afternoon tea.
Britannia Metal, for me at least, is not easy to fall in love with. Most of it is coated with a dull grey oxide that is harder than the metal itself and is the very devil to remove. But if you fancy hoarding mementoes of the emergence of Victorian middle class values that have shown no sign of rising in price for the past 25 years, there is a lot of six 19th century Britannia Metal teapots in the Law collection estimated at only pounds 80- pounds 100.
Charles Hull, author of the Shire Album on pewter, described to me how the country's stock of antique pewter got lost as china became fashionable at the end of the 18th century. Dented old pots and tankards, instead of being melted down and re-cast by pewterers, were sold to scrap metal merchants, who in turn sold them to tin refiners. They ended up as the "pot tinning" on steel horses' bits and stirrups - and in the last century as the tinning on fancy biscuit tins.
Britain's 17th century population of six million owned 30,000 tons of pewter wares. Now there is a tenth of that quantity in a population 10 times the size. But people have to start loving the stuff before such relative scarcity is translated into higher prices.
As curator of the Worshipful Company of Pewterers, Mr Hull is having the company's collection of 700-800 Britannia Metal wares buffed up and polished to look like new. There's no controversy over that, he says, but some collectors of the older pewter do prefer to leave its patina intact.
Dr John Richardson, a physicist, is one of a band of four dedicated collectors of church pewter who attend the same auctions and try to wheedle out of one another the names of Thames mudlarks who discover pewter wares. "If you wanted to invest," he says, "you wouldn't put your money into pewter." Except, he advises, Art Nouveau pieces. They have rocketed in value 200- 300 per cent in the past 10 years and are still rising.
The Sandy Law Pewter Collection, Phillips, 150 Christleton Road, Chester, Thursday 25 September (11am) (01244-313936). Hilary Kashden (0181-958 1018, fax 0181-958 2913). Pewter, by Charles Hull, Shire Album 280, pounds 2.25.Reuse content