The exhibition “Cartier” at the V&A was outrageously glamorous, with luminescent tiaras swimming in semidarkness, their diamonds flashing across the room. And while the exhibition was ephemeral, Cartier, the book that accompanied it, with nine expert essays and a myriad of dazzling photographs, is an enduring record of the Cartier firm.

The dynastic story began in 1847 when the twenty-eight-year-old Louis-François Cartier took over a jewelry business in Paris; within a decade his clients included Napoleon’s niece Princess Mathilde and the Empress Eugénie. The company flourished under Louis-François’s son, Alfred, and soared to global fame under Alfred’s three sons, Louis, Pierre, and Jacques. It helped that Louis, who became a partner in 1898 at the age of twenty-three, married into the Worth couturier family with its international clientele. Soon Cartier moved to the rue de la Paix, next door to the House of Worth and just around the corner from the Ritz.

Maison Cartier cherished its royal connections. In 1901, the year of Edward VII’s accession, Queen Alexandra ordered an “Indian chain” necklace of pearls, rubies, and cabochon emeralds, and in 1902 a wave of orders flooded in ahead of the coronation. That year Cartier opened its London shop, moving to its present location in New Bond Street in 1909, when it also opened its first New York branch. Its early, distinctive “Garland” designs, borrowing from eighteenth-century French classical decoration, appealed particularly to the American “Dollar Princesses”—rich heiresses then marrying into the British aristocracy. The Manchester tiara, for example—“a series of sweeping arcades appearing as open flaming hearts,” as Cartier describes it—was commissioned in 1903 by the Dowager Duchess of Manchester, the Cuban American heiress Consuelo Yznaga, a famous society hostess. She provided the jewels herself: more than a thousand brilliant-cut diamonds. Soon her friend Mrs. Cornelius Vanderbilt commissioned an imposing diamond necklace, and through such personal connections the customer base grew.

The three brothers shared the empire, with Louis running things in Paris, Jacques in London, and Pierre in New York, and they were always in tune with the times. Before World War I their most important designer was Charles Jacqueau, whose vibrant, colorful creations reflected the impact of Léon Bakst’s sensational sets for Scheherazade, staged by Sergei Diaghilev’s Ballets Russes in 1910. Jacqueau’s striking use of jade, sapphires, emeralds, turquoises, and lapis lazuli created a blue-green combination common in Islamic art but quite new to Western jewelry. This was typical of how Cartier designers often looked to other cultures or to the past for inspiration while challenging convention in a way that was startlingly modern.

The brothers’ own passions often drove changing styles. Both Louis and Jacques were collectors, moving in a circle of connoisseurs, curators, and writers and reveling in a huge range of influences: Gothic and Merovingian, Russian, Egyptian, Persian and Indian, Chinese and Japanese. The Egyptian sources, to take just one strand, were behind Cartier’s bold scarab brooches and extraordinary coffin-shaped vanity cases of the mid-1920s. These were not modest creations: one small vanity case has carved emerald sphinxes at each end wearing “royal head-dresses striped in sapphires and gold, and robes encrusted with onyx and diamonds.”

Louis’s particular interest was Asian arts and crafts, whose influence is felt in many of the abstract Art Deco designs. Jacques, meanwhile, collected Mughal art and jewelry, an inspiration for the multicolored Tutti Frutti series, in which clusters of brilliantly colored rubies, emeralds, and sapphires were carved to form leaves and flowers. Jacques made his first trip to India in 1911 for the Delhi Durbar following the coronation of George V and Queen Mary, and many of the maharajas he met remained clients for years. In 1928 Cartier made a spectacular many-layered necklace and headpiece of emeralds and diamonds for the maharaja of Patiala. Almost ten years later the maharaja of Nawanagar took possession of a jeweled sarpech (a traditional turban ornament) whose feathers of baguette-cut diamonds float up from a great golden-hued “tobacco” stone known as the Tiger’s Eye diamond. In the same year he commissioned a boldly geometric Art Deco piece, “one of the most important ruby necklaces ever created,” and three years later a unique necklace of blue, pink, and green diamonds.

Dashing designs were nothing without skilled workers to create them. The astonishing talent of the mounters, gem setters, and polishers from Cartier’s in-house workshops in Paris, London, and New York is evident in countless illustrations in the book. But for his clocks—like the mysterious Model A, whose hands seem to float within a block of rock crystal—Louis Cartier looked outside the company, collaborating with the Parisian clockmaker Maurice Couët and with the master watchmaker Edmond Jaeger for his wristwatches.

For the gemstones, the brothers wooed suppliers across the world. Sometimes they also bought jewels at auction or from people down on their luck: the jewels of the Russian imperial family, the Austrian imperial pearls from the last Habsburg emperor, “dethroned and in exile in Switzerland.” Many of the stones have their own history: the seven huge emeralds in an extraordinary shoulder clip owned in the late 1920s by Marjorie Merriweather Post, once the richest woman in America, were carved in Mughal India between the seventeenth and nineteenth centuries.

In Europe and America, Maison Cartier also kept a keen eye on the couturiers. When the fashion for backless dresses arrived in the 1920s, its designers created diamond collars that trailed down the spine and clips that were “fastened at the base of a plunging back.” With these went long necklaces “mirroring daringly deep V-necks and sitting flush on fashionably flattened busts.” Later Cartier introduced diamants mystérieux, single stones worn as hair clips or even on the eyebrows. But after the financial crash of 1929, the mood changed:

Suddenly it was all about bigger, brighter—and cheaper—creations, composed of what were once derogatively known as “semi-precious” stones: blue aquamarine, purple amethyst and yellow citrine.

Despite the crash, the parade went on. The company’s archives contain sketches of costumes for the glittering Jewels of the Empire Ball in London in November 1930, including elaborate head ornaments and tiaras. Tiaras became a Cartier specialty and were vigorously promoted by Jacques Cartier, an impresario of marketing and advertising.

Cartier’s jewels bedecked a string of glamorous, constantly photographed women: Elsa Schiaparelli, Marlene Dietrich, Maria Callas, Elizabeth Taylor, and Grace Kelly, as well as the superrich, such as Daisy Fellowes from the Singer family and the Woolworth heiress Barbara Hutton. The company cannily made sure that its gems were seen in Vogue and Harper’sBazaar. Cashing in on the movies, it loaned jewels to the stars: in How to Steal a Million Audrey Hepburn combines “Cartier diamonds with Givenchy fashion”; in The Thomas Crown Affair Steve McQueen sports a Tank Cintrée watch. Thin, rectangular Cartier watches twinkle casually in photos of Jackie Kennedy in 1969 and Andy Warhol in 1975. The royal bond also continued to boost Cartier’s image. Elizabeth II, who had a penchant for floral brooches, was often photographed wearing the famous Williamson diamond brooch, a diamond flower with a stunning pink diamond at its center, a stone discovered by Dr. John Williamson in Tanganyika (now Tanzania) in 1947 and presented to her at her wedding. The lasting flair for publicity is demonstrated by a dramatic portrait of Rihanna, photographed by Steven Klein and styled by Edward Enninful in 2016. Wearing a scroll tiara from 1902 and a choker worn by Clementine Churchill at the 1953 coronation, she could not look more up to date.

In the mid-twentieth century Cartier’s blend of tradition and modernity was orchestrated by Jeanne Toussaint, an “indomitable, unstoppable creative force” who served as its creative director from 1933 to 1970. As well as developing the classic geometric line of jewelry, Toussaint championed the witty and odd, like the flamingo brooch that the Duke of Windsor gave his wife, Wallis, in 1940, with wings picked out in geometrically cut emeralds, rubies, sapphires, and citrine. The most desirable of these playful designs were the three-dimensional creations such as the necklaces made for the Mexican film star María Félix: an articulated snake in 1968 and two entwined crocodiles in yellow gold, emeralds, rubies, and diamonds in 1975. As long ago as 1914 Cartier had begun using the combination of diamonds and black onyx to represent the fur of panthers and other big cats. Over the years, these cats with their glinting emerald eyes became an emblem of the house. One of the smartest, a black-and-gold panther perched on a huge emerald, was bought in 1948 by the Duke of Windsor for the duchess, who eventually possessed several “big cat” bracelets. Together the Windsors “amassed one of the greatest modern jewel collections of the twentieth century, centred on their shared passion for gems and jewellery design.”

This lavish book, with its gleaming photographs, sometimes feels like a high-society pirate’s chest stuffed with treasure. Recent studies of the diamond trade, as Michael Bycroft shows in Gems and the New Science, “are also histories of empire, gender, capitalism, coerced labor, and environmental decay.” But in Cartier there is no criticism of excess, no dark hint of politics or dubious deals, no allusion to the conditions of workers in diamond mines, and definitely no whisper of cash. Cost is irrelevant. The atmosphere is rarefied, the prose reverential. But while this ravishing book is a million miles away from “ordinary life,” it is beautiful to look at and disarmingly fascinating to read.

It’s quite a jump from Cartier jewels to Bycroft’s scholarly study of gems in the history of European science. But there’s some bling here too, particularly during the reign of Louis XIV, who was “famously partial to gems.” The 1691 inventory of the French crown jewels estimated their total value at 11.5 million livres—around $200 million today—and included such frippery as “151 buttons for a vest, each made of five diamonds.”

Bycroft, however, an associate professor in the history of science and technology at the University of Warwick and the coeditor of Gems in the Early Modern World: Materials, Knowledge and Global Trade, 1450–1800 (2018), is concerned less with sparkle than with science. The double history of gems—the relation between their value as luxury items and as objects of scientific inquiry—is the real subject of his study, and he coins the word “transmaterialist” to describe the way he approaches these intertwined fields. I’m not sure the term is needed, as many histories of science are inevitably multifaceted, but it gives him the flexibility, as he puts it, to examine “material things, material sites, the materiality of the natural environment, and political and economic life in contradistinction to intellectual life,” as well as “the interaction between gems and other material substances.”

Bycroft’s opening statement is both surprising and severe: “Strictly speaking, gems do not exist.” In current mineralogical classification, there is no separate category for gemstones. Yet this was not always so. During the scientific revolution, he writes, they were regarded not only as a “fully fledged class of mineral” but as the most important kind of stone. In 1609 Anselmus Boetius de Boodt, a doctor at the court of the Holy Roman Emperor Rudolf II in Prague, confidently described them as a category and arranged them in three classes: “transparent, semitransparent, and opaque.” Two centuries later all had changed: in 1808 a French encyclopedia declared firmly that the term pierres précieuses was “rejected in mineralogy as vague and misleading.”

When Boodt wrote, he was drawing on the Roman naturalist Pliny, who identified twenty-six “principal gemstones” in book 37 of his Natural History and divided them into classes according to color and then subsidiary groups depending on their origin. By contrast the later tradition of the medieval lapidaries valued gems less as luxuries than as possessors of distinct “virtues”—medical, moral, and magical powers. Archaic as that sounds, it could lead, Bycroft shows, “to surprisingly modern results,” namely the identification of “properties that were later studied under the heading of experimental physics, such as the ability to glow in the dark and to attract pieces of straw when rubbed.”

In the sixteenth century gem cutters and jewelers placed greater emphasis on hardness, as seen, for example, in The Treatises of Benvenuto Cellini onGoldsmithing and Sculpture (1569). Harder gems tended to come from the East, and value was thus signaled by provenance, increasingly so as trading expeditions, travel narratives, and maps identified particular regions and mines. As gems were divided into softer “occidental” and more valuable “oriental” stones, the terminology gradually became a description of quality, with little relation to geography. The importance of appraisal—of deciding between “good” and “bad” stones—was heightened under the gem-loving Louis XIV, as part of the codification of crafts that followed intense competition between the goldsmiths’ guild and the gem cutters’ guild. Two significant manuals by Parisian goldsmiths, Robert de Berquen’s Les Merveilles des Indes orientales et occidentales (1661) and Pierre de Rosnel’s Le Mercure Indien, ou Le Trésor des Indes (1667), laid claim to new expertise, sharpening the oriental/occidental distinction and defining new varieties of stones.

Valuation was important, since gems were major items of trade: in the late 1680s, for example, the traveler and cartographer Jean Chardin sent gold, coral, and emeralds to his brother Daniel in India, where their Portuguese partner used them to buy diamonds, which were then sent back to be sold in Europe. But buyers at home and abroad insisted on quality, and it was hard to know who could best assess this—the cutter, the connoisseur, the merchant, or the buyer? To add to the confusion, experts had varied opinions about which stones were “precious” or “semiprecious,” with emeralds and rubies often sliding between categories.

To the experimental philosopher Robert Boyle, gems were objects of scientific investigation. Boyle subjected his collection—bought, borrowed, or simply seen—to every kind of experiment: “He split them open, weighed them in air and water, suspended them in a vacuum, turned them into mirrors, dunked them in water, laid in bed with them, chewed them, smelled them, and much else besides.” Bycroft has identified at least 278 references to gems in his published and unpublished writings. Boyle studied their crystal form and measured their specific gravity, and his version of the hydrostatic balance, used to calculate density, was quickly adopted. He was interested in the qualities that were “priz’d by the Jeweller, or may be useful to the Physitian,” but his primary concern was proving his theories: first, that gems were formed in a liquid medium and, second, that all matter was corpuscular and in constant if invisible motion. One “imploding diamond,” a perfect stone that suddenly split with deep cracks, was taken to show “that there is a great deal of moving matter even in the hardest and most inert bodies.”

From Boyle onward experimental philosophy offered different ways of looking at gems, including their “optical and electrical behavior.” Moving from Renaissance natural history and the codification of the arts to experimental philosophy and physics, Bycroft shows how large state collections were particularly important to researchers. The aristocratic Charles-François de Cisternay du Fay examined gems in his studies of phosphors, light, and electricity in the 1730s and investigated double refraction, the ability of gemstones to divide rays of light in two. After Du Fay’s work a new emphasis was placed on measurement and quantification, illustrated by the classes and synoptic tables in Jacques-Christophe Valmont de Bomare’s Minéralogie (1762). Important in this phase was the large gem collection at the Jardin du Roi in Paris, which Georges-Louis Leclerc, Comte de Buffon, turned into a major research center. Here Louis-Jean-Marie Daubenton developed a method for defining gems in terms of color and quantifying their place on the solar spectrum, while the stress on measurement continued in the work of Buffon on double refraction and of Mathurin-Jacques Brisson on density.

As the new discipline of crystallography became more precise, gems were increasingly classified into new groups by correlating “physical characters,” such as hardness, density, and luminescence, with internal characteristics such as crystal form. At each stage the French savants worked with merchants and gem cutters, connoisseurs and instrument makers. But the most dramatic “transmaterial” phase came in the late eighteenth century, with the hunt to find the chemical composition of gems. This built on discoveries in several areas, including analysis of metals and ores in the German schools of mining, the role of “earths” and minerals in pharmacy, and the techniques of glassmaking. The last of these suggested that fluxes—substances used to melt sand in glassmaking—could also be used to soften gems so that they could be worked on by acids and “decomposed” in the laboratory. Louis-Nicolas Vauquelin finally succeeded in the decomposition of gems in 1799. Two years later, when René-Just Haüy published his Traité de minéralogie, he could declare that “emeralds are made up of 64.5 parts quartz, 16 clay, 13 beryllia, 3.25 chromium oxide, 1.6 lime, and 2 volatile matter.”

The analysis was startlingly new. Vauquelin had only recently identified beryllia and chromium. It also marked the death of gemstones as a distinct category. The appraisal of gems by transparency, color, and location—the “TCL scheme” that had endured in different forms for centuries—was thrown out as inaccurate and irrelevant. But not quite. Jewelers and purchasers still needed some mode of valuation that accommodated scientific findings to the “lapidary arts.” At the start of the uncertain science of gemology, writers competed to create new hybrid taxonomies. New collections were made, new tests undertaken, new tables drawn up. Evaluation, Bycroft argues, remains a subject far richer and more complex than suggested by the “four Cs” of today’s jewelry trade: “cut, color, carat, and clarity.”

Gems and the New Science is an original and substantial work of scholarship, its dense technical arguments backed up by copious footnotes, appendixes, and a lengthy bibliography. While illuminating the place of gemstones in the history of European science, it shows that “pure science” is never separated from commerce, power, and the concerns of the material world. Bycroft cannot quite strip gems of their mystery and magic, but he shows their history in a different light. Certainly after reading his book I will never look at an emerald brooch or Cartier tiara—not that I often have the chance—in quite the same way again.