When London jeweler and author Edwin Streeter published the fourth edition of his book “Precious Stones” in 1884, he devoted a chapter to the momentous diamond finds in South Africa that had begun in 1867. Not surprisingly, these stones, discovered in the British Cape Colony, quickly became known as “Cape diamonds.” By 1911, when W.R. Catelle, a later London merchant of prominence, published his book, “The Diamond,” the term designated diamonds with a slight-to-pronounced yellowish cast. What’s more, indicated Perry Wagner in his 1914 book, “The Diamond Fields of Southern Africa, “Cape” had been a color classification since at least the turn of the century.
Hence, for most of its life as trade jargon, the term “Cape” has served the purpose it did in the De Beer’s buying and sorting offices at Kimberley in the cartel’s early years: as pejorative shorthand for the presence of yellow in diamonds. Even today, the term conjures up an intrusive, value-draining tinge of yellow in the mind of the diamond professional.
But while “Cape” has been synonymous with yellow for more than 90 years, its rapid transformation from an origin to a color term within 25 years of its appearance has never been explained. Indeed, many people are unaware that the word ever had a geographical context. Here’s why.
Code Word for Cartel
Many of those who entered the diamond trade in the post-war era assumed gemologists were responsible for the modern-day meaning of “Cape.” Actually, they merely codified its exclusive usage as a color term. The man most instrumental for the enshrinement of “Cape” as a synonym for yellow in diamond lexicons was pioneering British gemologist Basil Anderson.
During extensive spectroscopic studies of yellowish and yellow diamonds in the 1930s, Anderson noted a correlation between the strength of light absorption bands common to such stones in the blue and violet regions of the visible spectrum and the strength of color observed in them. To underscore this relationship, he dubbed these telltale patterns “Cape lines” in an article published in 1943. By the end of the decade, all diamonds with such absorption lines were known as “Cape series” stones. The term “Cape” had been stripped clean of all prior geographical meaning.
How could it have been otherwise for a gem with a single distribution channel: the De Beers diamond cartel? In March 1914, two decades before Anderson began his spectroscopic studies, the diamond came under centralized market control when the companies and governments involved in mining of this gem in South Africa and South West Africa (now Namibia) signed a pact that set, among other conditions, production quotas and rough valuation formulas. Although aborted by the outbreak of World War I, this agreement set the stage for subsequent pacts in 1919 and 1925 that forged the De Beers cartel as we now know it.
For all intents and purposes, the geographical origin of diamonds meant little or nothing to the jewelry trade by 1935. That was the year following De Beers’ formation of the Central Selling Organization, its vehicle for selling rough to regular invited buyers in what are now known as “sights.” Few were aware of De Beers’ deft maneuverings to become the main buyer of diamond production from major sources not directly under its control. To the outside world, there was basically only one source for rough diamonds: De Beers. This is an important point to recall when discussing the lingering dominance of any diamond classification whose early use can be traced to De Beers. In short, the evolution of “Cape” into a color term is inseparable from the emergence of the De Beers cartel.
Matters of Finance
When South Africa’s diamond rush began in earnest with the discovery of non-alluvial deposits in 1870, it set the stage for eventual monopolization of the country’s mines. As Goddard Lenzen details in his monumental book, “The History of Diamond Production,” deep-earth mining required enormous capital outlays for heavy machinery that were beyond the means of the independent digger.
By 1880, when diggers could no longer afford to mine their claims, they were selling out in droves to European syndicates. In time, ownership of mines was concentrated in the hands of a few mighty syndicates, the two most famous of which were to be those of Barney Barnato and Cecil Rhodes (the founder and architect of the De Beers cartel). With backing from N.M. Rothschild & Sons, Rhodes bought out Barnato for 5.3 million pounds in 1889. From here on in, De Beers emerges as the chief distributor of rough diamonds—controlling anywhere from 40% of world production in the early 1900s to 80% today.
Once Rhodes realized his vision of cartel control, the term “Cape”, a slang word for South Africa among Europeans buying shares in diamond mining syndicates during the 1870s and 1880s, outlived its usefulness as a geographical term. Yet just when the term was ceasing to be shorthand for South Africa as a diamond cornucopia, it started to take on new life as shorthand for the most salient feature of the country’s diamonds: their tendency to be yellow, therefore a rare characteristic in this gem. The transition in meaning is marked in the 1904 English version of Max Bauer’s masterpiece, “Precious Stones,” where the German gemologist distinguished between “Cape” (South African stones) and “Cape white” (yellow-tinged stones).
But while Bauer restricted use of “Cape” as a color term to polished diamonds that in time would be called “top silver cape,” “silver cape” and “top cape” (J-M on the international color grading scale), the term was destined for an expansion of meaning beyond merely a hint of yellow. According to Wagner, the Kimberley office of the De Beers Diamond Syndicate used the following color ratings for what it called “Close goods” (octahedronally shaped roughs) in the early 1900s: blue white; pure white; fine white; white; fine or silver Cape; Capechaste first-grade water (stones, says Bauer, with a greenish tinge), and second bye-water.
In 1930, writes Godehard Lenzen in “Diamonds and Diamond Grading,” the trade agreed on a color classification system for polished goods comprised mainly of terms derived from South Africa’s diamond areas: Jager (finest blue-white); river (blue-white); top Wesselton (fine white); Wesselton (white); top crystal (finest silver Cape); crystal (silver Cape); top Cape (fine Cape), and Cape. While these ratings have been supplanted by GIA letter grades, the term “Cape” remains in active use as much an insider code word for yellowish diamonds as it was nearly a century ago.
Please note: this profile was originally published in 1992 in Modern Jeweler’s ‘Gem Profiles/2: The Second 60’, written by David Federman with photographs by Tino Hammid.
The 9.98-carat Cape diamond shown on this header page is courtesy of Christie’s New York.
