In a major scientific breakthrough, a team from the University of Bristol has finally solved a centuries-old mystery: why does exploding gold, an explosive known since the 16th century, produce purple smoke when detonated?
This discovery solves a mystery that has fascinated scientists since the days of alchemy and sheds new light on the fascinating world of early explosives.
Bright gold was first discovered by alchemists in the 16th century and was the world’s first known high explosive.
It is a mixture of various compounds, with ammonia being an essential component that contributes to its explosive nature.
Although exploding gold has been known and studied for centuries, one question has remained unanswered: What causes the purple smoke released when it explodes?
The peculiar purple smoke was first noticed by the German alchemist Sebald Schwaertzer in 1585.
Over the years, the phenomenon attracted the attention of prominent chemists such as Robert Hooke and Antoine Lavoisier. But the cause of this colorful display remained a mystery.
Fast forward to today: Professor Simon Hall and his Ph.D. University of Bristol student Jan Maurycy Uszko took on the challenge of solving this puzzle. Professor Hall was enthusiastic about the team’s contribution to understanding this historical material.
Their innovative experiment was to create exploding gold and detonate small amounts of it on aluminum foil. They then captured the resulting smoke using copper nets for detailed analysis.
Using a transmission electron microscope, the team made a groundbreaking discovery. The purple smoke contained spherical gold nanoparticles.
This confirmed the long-held but unproven theory that the coloring is actually due to gold playing a role in the formation of smoke.
After unraveling the mystery of the purple gold smoke explosion, Professor Hall and his team don’t stop there.
They plan to use this method to study the clouds produced by other metal fulminates, including platinum, silver, lead and mercury. These substances used throughout history still pose unanswered questions about their explosive behavior.
For those interested in the intricacies of this discovery, the team’s research paper, titled “Explosive Chrysopoeia,” is available on the website arXiv.
The central theses
This breakthrough by the University of Bristol team not only solves a historical mystery, but also enriches our understanding of early explosives.
The discovery that the striking purple smoke of exploding gold is due to gold nanoparticles opens new doors in the study of explosive materials and continues to bridge the gap between ancient alchemy and modern chemistry.