Valentine Roses and Diamonds by the Numbers
According to a survey by the National Retail Federation, 37.8 percent of Americans will buy flowers for Valentine’s Day 2015, spending a total of $2.1 billion. About Flowers estimates that 250 million roses will be produced for Valentine’s Day. That same NRF survey said that nineteen percent will treat their significant other to something sparkly; jewelry spending will total $3.9 billion. Two years ago, CNN estimated that $4.4 billion would be spent on diamonds, gold and silver. That’s not surprising to the Amador Ledger Dispatch reporter who reported that 2.6 million Americans get married every year, with ten percent of all marriage proposals occurring on Valentine’s Day. The U.S. Census proclaims Valentine’s Day is the single most popular day for wedding proposals out of the entire year.
Rose-Cut Diamonds
There’s a way to combine both gifts. There are rose-cut diamonds that were quite popular in the 1700s, and are making a comeback as a vintage gem. However, the rose-cut does not sparkle as much as other cuts. One of the most famous rose-cut diamonds is the Orlov Diamond, which is part of the collection of the Diamond Fund of the Moscow Kremlin and can be traced back to an 18th century Hindu temple in India. It was mined in south India, probably at the Kollur Mine, which was one of the most productive diamond mines in the world. Hearts of Fire reports that the stone is white with a faint bluish-green tinge and is estimated to weigh 189.62 carats.
Rose-Colored Diamonds
Don’t want the rose-cut diamond? How about rose-colored diamonds? The Gemological Institute of America Inc. (GIA) reports that ‘fancy diamonds’ – diamonds with color – can be even more valuable than colorless diamonds: “Diamonds with red or reddish colors are extremely rare and highly valued. Pure pinks are more popular than diamonds that are purplish, orangy, brownish, or grayish. Trade professionals market some very attractive stones in this category as “rose-colored,” and some stones with purplish tints as “mauve” diamonds.”
If you visit the Smithsonian National Museum of Natural History Gem Gallery you might get a glance at the DeYoung Red Diamond, one of the largest known natural fancy dark red diamonds. The Museum reports that it is “a modified round brilliant cut diamond that has a clarity grade of VS-2 and weighs 5.03 carats. The diamond was acquired by a Boston jeweler, as part of a collection of estate jewelry in which it was wrongly identified as a garnet. The cause of the extremely rare deep red color of certain diamonds is not understood, but might be related to defects in the crystals’ atomic structure.”
Our previous post, The Diamond Shortage: The Hunt for Kimberlite and New High Quality Synthetics, talked about how rare it is to find a diamond, never mind one of color or such significant value. Most diamonds are found in kimberlite pipes, and few pipes yield enough diamonds to be worth the effort of mining them. (Read Kimberlite: A Girl’s Best Friend? for more details.)
Synthetic Diamonds
The average person might not be able to afford a mined diamond, nevermind a rose-cut or rose-colored one. That’s why synthetic stones have become big business. These include high-pressure high-temperature (HPHT) diamonds and laboratory-grown diamonds formed by Chemical Vapor Deposition (CVD), techniques which have improved to the point that these products are nearly indistinguishable from natural diamonds. Diamonds can also gain color by artificial irradiation. Today, the identification of synthetic and treated diamonds has become one of the major challenges for the gem industry.
FT-IR Spectroscopy
FT-IR spectroscopy can be a useful tool for buyers and sellers to determine whether diamonds are natural and what type they are. FT-IR (Fourier Transform Infrared) spectroscopy produces an infrared absorption spectrum that represents a fingerprint of the sample with absorption peaks which correspond to the frequencies of vibrations between the bonds of the atoms making up the material. Because each element is a unique combination of atoms, no two compounds produce the exact same infrared spectrum.
Diamonds are unique among gemstones because they are composed of a single element (carbon), while virtually all other gems contain multiple elements including significant amounts of oxides. The infrared spectrum of diamond is equally unique and can be used to easily confirm that a stone is actually a diamond. A diamond consists of crystalline carbon and the extreme conditions required to create them also provide a way for trace amounts of other elements to be trapped in the crystal matrix. The most important trace element is nitrogen, which can be found in different forms in the diamond crystal. These nitrogen aggregates create unique features in the infrared spectrum and are key in classifying diamonds. Hydrogen, boron and carbonates are other important trace elements, all of which have identifiable features in the infrared spectral region.
While it is easy to confirm that a stone is a diamond, it is much more difficult to determine if it is synthetic or treated. The infrared peaks corresponding to the nitrogen aggregates or presence of other elements can be used to provide valuable evidence that a stone is not natural. Numerous gemological laboratories employ FT-IR on a daily basis to characterize diamonds and other gemstones. FT-IR is used extensively to provide “evidence” about treated or synthetic diamonds, but does not provide a definitive answer because of the tremendous variation in natural stones. This is like a medical diagnosis. For a high value gemstone you really want an experienced gemologist to make a diagnosis based on the results of multiple tests. FT-IR being one of the most useful.
Read Analysis of Diamonds by FT-IR Spectroscopy to learn more, and to read several examples of how the combination of an FT-IR spectrometer with an optimized accessory provides multivariate statistical analysis techniques to provide a rapid, reliable information source of great importance to classifying gemstones.
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