Contemporary Art Market: Showman presents dazzling display of crafted vulgarity: As Jeff Koons has his first exhibition in Britain, one of the country's greatest artists returns home

THE MOST spectacular show in any London gallery this week is the Jeff Koons retrospective at Anthony d'Offay's (9, 21, 23 and 24 Dering Street, W1), the first exclusively of his work in Britain. One gasps at Koons's monumental vulgarity, but the total effect is dazzling.

A 7ft bear embraces a startled policeman in the gallery window; the wooden sculpture, based on a humorous postcard Koons bought at Heathrow, carries the show's top price of dollars 425,000 ( pounds 283,000). Koons employs the wood carvers of Oberammergau in Bavaria, who usually make Madonnas for the tourist trade, to produce his sculptures. And a slight whiff of sanctity hovers over the secular motifs; there is a spectacular vase of carved and painted flowers at dollars 225,000 ( pounds 150,000) and a 3ft poodle for dollars 100,000 ( pounds 66,000).

He gets his marble works carved in Italy. D'Offay's has a head and shoulders Self-portrait emerging from a marble iceflow at dollars 250,000 ( pounds 166,000). His porcelain is made in Germany; two naked children, 4ft high, studying a sexually arresting bunch of flowers are priced at dollars 250,000.

Just to underline the fact that Koons is the showman who has the idea, not the craftsman who makes the art work, one should mention the bronze Aqualung offered at dollars 225,000. He took an aqualung with its oxygen cylinder, rubber tubes and canvas shoulder straps to a foundry in upper New York State and had the whole thing cast in bronze; the Koons contribution was minute quality control to ensure that every texture was reproduced correctly.

While d'Offay devotes his main galleries to high-profile artists like Koons, he opened a new space earlier this year, at the back of 24 Dering Street, to show emerging talent. The present exhibit is a work by the 35-year-old Japanese artist, Yukinori Yanagi, called Union Jack Ant Farm. It comprises 16 national flags of former British colonies made from coloured sand in perspex boxes which are connected by transparent plastic tubes; a colony of ants has been introduced from the back of the art work - where they are fed daily; the ants are gradually deconstructing the flags by walking through the sand boxes and tubes. It costs dollars 40,000 ( pounds 26,000).

It may not sound saleable but d'Offay's two former 'emerging' exhibits have found prestigious buyers.

The Anthony Reynolds Gallery, over the road from d'Offay at 5 Dering Street, is also attracting international attention to the 'emerging' market with a show that stands normal curatorial practice on its head.

At one week's notice, Reynolds invited 72 different people to bring one art work they admired to the gallery and leave it for exhibition.

An abstract by James Smeaton, an Australian artist whose work has never been shown in Britain, was sent by Federal Express from New York and sold on the second day to a Californian collector for pounds 1,500.

Charles Saatchi, Britain's most voracious collector, has bought a work called Pure Filth, contrived from glass, dust and perspex tubing, by Emma Smith - who has never previously exhibited - at pounds 800.

(Photographs omitted)