Thanks, this was the sentence that was missing from the article and made me confused knowing that humans are basically made of carbon, but glass is not.

The article should have said “a glass”, not “glass”. The former is a term from physics that is different from the lay-mans’s “glass”. https://en.wikipedia.org/wiki/Glass_transition:

“The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. An amorphous solid that exhibits a glass transition is called a glass.”

The Nature article is clearer. https://www.nature.com/articles/s41598-025-88894-5: “Glass forms when a liquid is fast cooled preventing crystallization, across a reversible process known as the glass transition.

[…]

Here we demonstrate that material with glassy appearance found within the skull of a seemingly male human body entombed within the hot pyroclastic flow deposits of the 79 CE Vesuvius eruption formed by a unique process of vitrification of his brain at very high temperature”

The layman’s term includes such things as safety glass, which may have polymer layers.

So, confusingly, not all glass is “a glass”, and not all glasses are glass.

However, I've not been able to find much on carbon-oxgen based glass. It's possible to make glass out of CO2 gas, under high pressure. However, at standard pressure, the glass boils off into CO2.

There are definitely some unconnected dots in the story. I have a sense that what is needed is to reproduce this allegedly vitrefied organic material in the lab.

Could this actually be more like a plastic? Some thermoplastics share characteristics with the category of glass, like having amorphous structure and a gradual softening resembling glass transition temperature. Conversely, we could say that glass, such as a common silica glass, is a kind of thermoplastic.

In:

https://en.wikipedia.org/wiki/Thermoplastic

we have language like "[a]bove its glass transition temperature and below its melting point, the physical properties of a thermoplastic change drastically without an associated phase change."

Also:

https://en.wikipedia.org/wiki/Glass#Polymers

"Many polymer thermoplastics familiar to everyday use are glasses."

https://en.wikipedia.org/wiki/Glass#Non-silicate_glasses

"Besides common silica-based glasses many other inorganic and organic materials may also form glasses, including [...] nitrates, carbonates, plastics, acrylic, and many other substances."

> humans are basically made of carbon, but glass is not

A glass is something that underwent a glass transition (that looks like a liquid at the atomic scale but behaves like a solid microscopically, resulting from cooling a liquid too fast to let it crystallise). It can be made of a huge diversity of things: pure elements (like carbon or sulphur), some metallic alloys, oxides, sulphides, fluorides, polymers, etc.

But the article says "glass", not "a glass".

Using “glass” as a strict equivalent for “silicate glass” is incorrect. Metallic glass is glass. Not the glass you are used to, but still glass.

I'm not convinced that that is common usage. Maybe in technical circles.