Joel Rosenthal at the Metropolitan Museum: Hidden treasures Poppy brooch, 1982. Diamond, tourmalines and gold. Private collection. "Jewels by JAR" is at the Metropolitan Museum of Art, New York Source: Photograph by Katharina Faerber. Courtesy of JAR, Paris Geranium brooch, 2007. Diamonds, aluminium, silver and gold. Private collection Source: Photograph by Jozsef Tari. Butterfly brooch, 1994. Sapphires, fire opals, rubies, amethysts, garnets, diamonds, silver and gold. Bracelet, 2010. Diamonds, silver and platinum. Courtesy of JAR, Paris. Lilac brooches, 2001. Diamonds, lilac sapphires, garnets, aluminium, silver and gold. Tulip brooch, 2008. Rubies, diamonds, pink sapphires, garnets, silver, gold and enamel. Zebra brooch, 1987. Agate, diamonds, a sapphire, silver and gold. IN 1978 Joel Rosenthal, then a fledgling designer with a passion for gems, opened a small shop off Place Vendôme in Paris. He and Pierre Jeannet, his partner, named it JAR after the designer's initials (his middle name is Arthur). Mr Rosenthal, who was born 70 years ago in the Bronx, says, "I wanted to fall flat on my own face or make my own name." He certainly succeeded in the latter. Mr Rosenthal is insistent that he had no powerful backer, either social or financial. Passers-by were not encouraged to drop in. The only publicity was word of mouth. Yet the famous and the rich soon found their way to his door, lured by the uniqueness of his creations. The jeweller combs the world for quality gems, constantly expanding his range with unusual, even unfashionable stones, including green garnets, pink sapphires and black diamonds. His pieces are often unusually large and deeply three-dimensional. A brooch of two life-size, gem- laden lilacs is instantly recognisable as being by JAR. These are jewels for the chauffeured, not for those who need coats. Mr Rosenthal has written that "beauty, art and luxury are inseparable from happiness." His prices are not listed, though there are clues. In May 2012 Lily Safra, a philanthropist, auctioned 18 of her JAR pieces at Christie's in Geneva in aid of charity. They fetched nearly $11.5m. Among them was a 37.2-carat diamond she had brought to Mr Rosenthal. "I can camouflage that," said the charmer, who can also be blunt. He wrapped it in the twisting stem of two poppies made of pink and green tourmaline (pictured). Eleven years after his only public show so far, at London's Somerset House, Mr Rosenthal is about to become better known. Some 400 pieces are on view in "Jewels by JAR" at the Metropolitan Museum of Art. Many were made over the past decade and all are loans. This is the jeweller's first American retrospective and the museum's first display of "a contemporary artist in gems." Tom Campbell, the director, believes people will see how the Met's jewellery collection, which spans 2,000 years, has influenced Mr Rosenthal. In turn, JAR's jewels will enable them to see the Met's collection "with fresh eyes." These adornments and objets d'art, ranging from an amusing engraved bagel made of wood to a translucent amber pocket watch, occupy a single, spacious oval gallery. The walls are dark salmon in colour. The light is dim except inside the velvet-lined vitrines, which line the gallery's perimeter and also stand freely within the central space. The effect is dramatic. The pieces are loosely arranged by category: flowers, animals, sea life. There are plump ruby roses and camellias from a fairy-tale garden. In one small vitrine a flat-faced hellebore covered in diamonds and violet sapphires rests alongside its case - a round snowball made from a smoky rock-crystal studded with diamond snowflakes; apt for a flower that is also called the Christmas rose. In JAR-land even the ferns are pavéd in diamonds. Among the beasts, a soulful zebra-head brooch carved from agate wears a diamond halter and plumed headdress. The exhibition ends with a wall of butterfly brooches, each one larger-than-life-sized and closely set with intensely coloured gems - including fire opals, amethysts and garnets. Mr Rosenthal wants visitors to look at his creations without being distracted by long explanatory captions or audio guides. This is effective; all attention is on the jewels. But the Met is not a shop where such a presentation would suffice. There ought to be a catalogue, for instance, with information about the rarity and source of the gems, comparisons with JAR's most inventive contemporaries and comments from clients about commissions. Instead, the museum shop is offering only luscious picture albums (a short one with a biographical essay priced at $40 and a giant edition, which costs $800). The museum deserves praise for exhibiting the work of an exceptional living jeweller, but not for letting him call the shots (even basic information, such as the size of the pieces, is missing). This is a sensational advertisement for JAR, as well as a fantastical, occasionally funny show, which is often very beautiful. For the visitor, that is both terrific - and not enough.