Science & Technology

Scientists probe origin of strange dark blue glass unique to Australia

By T.K. Randall
October 1, 2025 ·  6 comments

Image: Aerial view of the Sydney Opera House
Credit: James Cridland / CC BY 2.0 (adapted) Exhibiting a striking dark blue hue, this curious glass gained renewed attention when it was discovered that it was distinctly different to other similar materials found strewn across the same region.

Known as tektites, materials of this nature are typically formed during asteroid impacts and these were thought to be no exception - most likely they were linked to an impact that occurred around 800,000 years ago.

Now, though, a new study into the more unusual tektites found in the region has revealed that they may in fact be several million years older than the other, more common examples.

This also means that they were produced by an as-yet unknown impact in the distant past."These glasses are unique to Australia and have recorded an ancient impact event we did not even know about," said geochemist and study co-author Fred Jourdan.

"These tiny pieces of glass are like little time capsules from deep in our planet's history."

The impact responsible for producing them is now thought to date back some 11 million years, though it is unclear exactly where the impact took place.

"What makes the discovery even more intriguing is that, although the impact must have been immense, scientists are yet to locate the crater," said Jourdan.

"Understanding when and how often large asteroids have struck Earth also helps us assess the risk of future impacts, which is important for planetary defense."

Source: Live Science | Comments (6)

Tags: Australia, Glass