The Great Appeal of Platinum: Catalytic Properties
Platinum has many more applications outside watches and jewellery, most of which are used in industry. So anyone who has ever benefited from, or experienced the benefits of, a catalytic converter has actually experienced how platinum makes a difference. How? Well, I’m glad to assume you asked this question because the catalyst in catalytic converters […]
Platinum has many more applications outside watches and jewellery, most of which are used in industry. So anyone who has ever benefited from, or experienced the benefits of, a catalytic converter has actually experienced how platinum makes a difference. How? Well, I’m glad to assume you asked this question because the catalyst in catalytic converters is platinum, typically, so if you have owned a car made after 1975, then you are indeed a person who owns just a little bit of platinum. While electric cars do not require catalytic converters, platinum is still the go-to material in diesel, gasoline and hybrid cars, as well as in the innumerable other types of engines (including electricity generators) as the world struggles to fight pollution from the burning of fossil fuels.
An interesting point we will explore later is the case for rhodium, which is also in the platinum family of metals. This metal shares many of platinum’s characteristics, including its catalytic properties. Rhodium though is extraordinarily expensive, becoming in 2021 the world’s most expensive metal, at more than US$80 per gramme at the most conservative end. At its highest, rhodium was trading for US$744 per gramme. Platinum is thus still the more cost-effective option, and not by a little.
This means platinum does have practical benefits that make it less volatile, price-wise, than its alternatives and, for watch and jewellery purposes, gold. Indeed, there are times when gold is actually more expensive than platinum. We actually live in such a time right now, with platinum trading at roughly US$30 per gramme and gold currently selling for double that. This has been the case for some time now, and it was perhaps only in the recession of 2008 that platinum traded above gold. You will no doubt be rushing off to Google this now and that is just fine — you can come right back because this is not the only unusual nugget here for scarcity and value warriors. In fact, just read this particular segment in front of your laptop or your phone because you will feel the need for information confirmation virtually constantly. Be careful not to fall too deep into any rabbit holes though because there is plenty of confusing and apparently contradictory information out there.
Demand for platinum remains relatively stable, given its industrial applications, whereas gold’s practical application is as an economic hedge (typically against inflation) and a publicly recognised store of value. Most economies no longer use the gold standard, but virtually every government has gold reserves. This means tonnes of bullion simply sitting in vaults around the world, and no, we will not be getting into any conspiracy theories. By way of contrast, no country is known to have platinum reserves. Adding to this is the fact that the US considered platinum so vital as a strategic resource that it regulated its use during World War I (President Woodrow Wilson’s Platinum Policy), and once again during World War II. This took the metal out of play for most jewellers, effectively ending a brilliant run by all the fine jewellers of the era, from Cartier and Van Cleef & Arpels to Bvlgari and Tiffany & co. It was a different story for watchmaking.
Switzerland, like the US, made platinum a strategic asset, like gold and silver. One of the reasons for this was that watchmaking was hugely important for the economy (even more important than it is today), and watchmakers had been lobbying for legislation that protected against fraud. These same protections already existed for gold and silver, but platinum was not covered as it had not been used much in the trade since its official discovery and classification was only in the 18th century. Indeed, some evidence suggests that platinum was used to adulterate gold, so legal standards were needed to protect the purity and sanctity of gold. In any case, these sorts of legal protections were not done for the express benefit of any industry, and were instead undertaken to establish standards. These days, such standards define the use of precious metals in watchmaking and jewellery. For example, the exact percentages of gold in alloys is standardised worldwide, thanks to such measures. This is also why platinum 950 is the standard order for platinum in typical use, and this simply means 95 per cent platinum. It is not specific to watchmaking, although the precise wording, platinum 950 is Swiss.
So in the early 20th century, platinum was finally making an appearance in horology, but still in pocket watches. The state of obtaining pure platinum and then alloying the same was hard going at first. Since platinum comes with other related metals, such as rhodium, iridium and palladium, to name a few, it first has to be purified. In fact, some of those other materials were also mistakenly labelled platinum, leading to all manner of problems. This was how the La Tolita pre-Columbian (circa 600 BCE to 200 CE) culture used platinum, in combination with gold. We think they worked with platinum in powdered form, sintered with gold in a similar form, then used simple tools to shape the resulting alloy. Unfortunately, this culture did not leave any written records, and the dismissive attitude of the Spanish towards platinum (they regarded it as an impurity that adulterated the gold they lusted over) did not help. Indeed, the name platinum comes from Spanish references to the metal as La Platina, or little or lesser silver.
A major issue in working pure platinum was simply reaching the metal’s melting point, roughly 1,769 degrees C. By way of contrast, gold melts at approximately 1,065 degrees C and iron at 1,538 degrees C. This is an issue for purification too, but here chemical processes work, to an extent. Platinum (and platinum group metals) are largely unreactive, with platinum not succumbing to any acids at room temperature. European researchers were familiar with aqua regia though and this combination of nitric acid and hydrochloric acid can dissolve platinum, just as it dissolves gold. Iridium and osmium do not react with aqua regia and can thus be separated from platinum. Using aqua regia, 18th century metallurgists were able to create gold-platinum alloys that could be worked, but they had not realised that other metals such as palladium might get in too since it dissolves in aqua regia too.
Achieving the necessary temperatures to turn platinum molten was only possible with the invention of the oxyhydrogen torch in the 19th century, which is when various industrialising European nations tried to find applications for platinum. The Russians and the British even fashioned coins out of platinum, though these never gained favour. Remember this the next time you play a computer game in a mediaeval setting that features platinum coinage or objects, or read a fantasy novel that features the same.
As mentioned earlier, platinum is today mainly used for industrial purposes, with the automotive industry using up to 50 per cent of available material (projected as 41.45 per cent for 2022 on Statista, the source of all production and usage numbers used in this article). The estimated percentage for watches and jewellery stands at 21.27 per cent; investments do not even warrant a predicted percentage. Gold, by way of contrast, is estimated to be used by the watch and jewellery sector, and for investments, to the tune of 90 per cent. One effect of this is to make platinum relatively rare in watches and jewellery, because of competition with other players. Unusually, there is enough platinum to solve this problem, but mining firms are apparently reluctant to increase supply for fear of damaging prices, and not only for this material.
We will close this segment with a note about density, the defining characteristic of platinum. In pure forms, platinum is just 8 per cent denser than gold, and that number might surprise. This is primarily because we are often told that platinum is 60 per cent denser than gold, which is a reference to platinum 950 and 14k gold. When it comes to 18k gold, the number is approximately 30+ per cent. The practical effect of the resulting confusion from these numbers is primarily felt most viscerally in watches and jewellery, but the effect overall is that the general public has the idea that platinum is so heavy as to be impractical to wear.
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