Diamonds aren’t all the time colorless; they can be blue, yellow, inexperienced and even pink. However what makes these jewels are available different hues?
At their base, diamonds are fabricated from a single aspect: carbon. “It is simply pure carbon,” solid into treasure underneath very excessive pressures, stated Luc Doucet, a senior analysis fellow of geology at Curtin College in Australia. They usually type deep beneath Earth’s floor, greater than 100 miles (161 kilometers) down within the planet’s mantle. Right here, the strain and temperature are excessive sufficient for the carbon atoms to bind collectively in a decent lattice.
After forming, diamonds must rise to the floor in a short time for his or her lattice to remain intact. This often occurs when volcanic eruptions eject the rocks up from the depths. If a diamond stays within the deep, they could soften or rework into graphite over the course of hundreds of thousands of years.
“We’re really very fortunate that we even get to search out them, as a result of they must then be expelled from the deep Earth,” stated Gabriela Farfan, the Coralyn Whitney curator of gems and minerals on the Smithsonian Nationwide Museum of Pure Historical past.
The vast majority of diamonds are colorless. However there are a few methods regular diamonds can flip into “fancy colour diamonds,” Farfan stated.
First, like all minerals, diamonds can get impurities once they type. These flaws are parts apart from carbon that get built-in to the gem’s construction. However as a result of carbon molecules are so small and really tightly packed, only a few parts can get launched into diamonds. “There aren’t very many parts that may substitute in,” Farfan stated.
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Nonetheless, there are just a few exceptions. Nitrogen, carbon’s neighbor on the periodic desk, can sneak into the diamond’s lattice, making yellow or orange diamonds. Boron, one other aspect with a small atomic radius, could make hanging blue diamonds, such because the well-known Hope Diamond.
Radioactive radiation also can make diamonds inexperienced. This could occur if the neighboring rocks close to the gems have uranium, which may “expel atoms to create vacancies” within the diamond’s construction, Farfan stated.
Diamonds also can get their colour by means of structural deformities. That is how pink and crimson diamonds type. These stones get these hues as a result of their carbon lattices develop into warped when they’re deep contained in the planet.
A diamond needs to be squished in simply the precise approach to tackle a pinkish or bright-red hue. “It is type of like Goldilocks,” Doucet stated. If a diamond is put underneath an excessive amount of strain, it could actually flip brown; if it isn’t underneath sufficient strain, it stays colorless. “There are a whole lot of brown diamonds, and really, only a few pink diamonds,” Doucet famous.
Curiously, due to how pink and crimson diamonds type, scientists can analyze these gems and perceive precisely the place and when in Earth’s crust they originate. The geologic processes of an space leaves behind a signature in a diamond’s deformities. “So on this approach, pink [and red] diamonds are the one ones you would probably try to hint again to a geographic area,” Farfan stated.
As an illustration, Doucet studied pink diamonds from the Argyle mine in Western Australia, one of many largest diamond mines on this planet. By wanting on the gems’ construction, he and his colleagues pinpointed that the stones had been made through the breakup of Earth’s first supercontinent 1.3 billion years in the past. The outcomes had been revealed in a 2023 examine within the journal Nature Communications.
Farfan identified that the Winston Diamond, which was lately placed on show on the Smithsonian Nationwide Museum of Pure Historical past, is shiny crimson. And primarily based on an evaluation revealed within the journal Gems & Gemology, it seemingly got here from someplace in Venezuela or Brazil.
Finding out these fancy colour diamonds can be a great tool for science. They might help researchers perceive what was occurring inside Earth and the way carbon cycles shifted all through the planet’s historical past, Doucet stated.
These diamonds are particular as a result of “Earth produced them underneath such distinctive circumstances,” Farfan stated. “It is only a miracle that it even exists within the first place.”
