A burning candle produces about 1.5 million tiny diamonds every second.

In 2011, Professor Wuzhong Zhou and his research team at the University of St. Andrews in Scotland discovered that candle flames contain four types of carbon. Using a novel sampling technique with anodic aluminum oxide films, they captured particles from the center of a flame. They found that the process creates diamond nanoparticles, fullerene molecules, graphite, and amorphous carbon.The researchers estimated that a standard candle generates roughly 1.5 million diamond nanoparticles every second. These diamonds are incredibly tiny, measuring only a few nanometers in diameter. For comparison, a human hair is about 80,000 to 100,000 nanometers wide. This means the diamonds are far too small to be seen or collected for jewelry.The discovery was surprising because diamond formation usually requires extreme pressure and high temperatures deep within the Earth. In a candle, the hydrocarbon molecules from the wax are broken down and then rearranged into these structures within the flame's reaction zone. However, because of the intense heat and presence of oxygen, the diamonds are oxidized almost immediately. They convert into carbon dioxide before they can leave the flame, making them a fleeting scientific marvel.