Special Report - Jewelry - Enamel's Molten Beauty - NYTimes.com Enamel lacks the intrinsic value of gold and diamonds, but among connoisseurs, glass melted onto the surface of another substance can inspire the same degree of devotion as an Old Master painting. Khalili Collection, courtesy of Khalili Family Trust A silver-gilt charger with cabochon emeralds, sapphires and amethysts, turquoise, smoky quartz and citrine, from "Enamels of the World 1700-2000," at the State Hermitage Museum in St. Petersburg. "Enamels of the World 1700-2000," at the State Hermitage Museum in St. Petersburg through March 14, is a sprawling exhibition of 320 enamel pieces that depicts the technical and geographical range of this rare and sumptuous art, shown for the first time in a uniquely global context. The items are drawn from a collection of approximately 1,200 pieces belonging to Nasser D. Khalili, a scholar and philanthropist born in Iran in 1945 and based in London. Known for his comprehensive collections of Islamic and Japanese art, Dr. Khalili spent decades assembling the finest examples of enamel from every major genre, including jewelry, furniture, tableware and timepieces. There are novelty items, such as a perfume spray shaped in the form of a pistol, an evening bag, designed by Aloisia Rucellai in 1968, in which enamel and engraved gold replicate the folds of moiré silk and a festively decorated casket commissioned by Elisabeth, Queen of Romania, in 1897 for one of her favorite artists. "The public will be astounded by the diversity of the Khalili material," said Geoffrey Munn, managing director of Wartski, an art and antique dealer in London. He hasn't followed the clichéd routes of enamel. He's got examples of Limoges and less well-known Russian craftsmen, like Pavel Ovchinnikov. The scale is enormous. The craft of enameling is more than 3,000 years old. Dr. Khalili, however, deliberately dated his collection from 1700 because examples of enamel manufactured before the 18th century are virtually impossible to find, and lack the precision and beauty of the later pieces, he said. The exhibition juxtaposes works created in the major enameling centers - Western Europe, Russia, America, Iran and India, China and Japan - placing a special emphasis on the impact that itinerant craftsmen had on the evolution of the art. From the Swiss watchmakers whose painted enamel timepieces enthralled the Mughal and Persian courts to the Chinese cloisonné enamels that arrived in Japan during the early 19th century, the cross-pollination of enameling techniques and styles is evident in the Khalili collection's pioneering scope. Mikhail Piotrovsky, the director of the State Hermitage Museum, remarks in his preface to the heavyweight volume accompanying the exhibition: "The ability to absorb outside influences without losing a very particular feeling for national identity is one of the most notable attributes of the Russian enameler." That was certainly true in the case of Peter Carl Fabergé, whose mastery of cloisonné, while influenced by Japanese moriage enamel, inspired the jury at L'Exposition Universelle of 1900 in Paris to label his work "craftsmanship at the very limits of perfection." In cloisonné work, enameled color zones are separated by fine inlaid wires, while in moriage they are separated by raised porcelain ridges. "Enamels of the World" pays homage to Fabergé"s way with color, much as it celebrates René Lalique and Cartier, two jewelers who helped define enamel in the 20th century. But the often underappreciated expertise of Japanese enamelists is a revelation. The art reached its zenith in Japan during the Meiji period, when the workshops of Namikawa Sosuke in Tokyo and Namikawa Yasuyuki in Kyoto perfected the delicate process of baking enamel. "The maximum times you put any enamel into the kiln is four," Dr. Khalili said. But the Japanese pushed that limit to achieve more subtle effects. The exhibition looks at the variety of techniques used to create such minutely detailed representations, including champlevé, plique à jour and painted enamel. More compelling, however, is the exhibition's look at patronage, a narrative that unfolds across three centuries, detailing which gifts were chosen for the world's imperial households when gold and diamonds simply wouldn't do.