I used to work with a glass archaeologist. I remember when I first saw some pieces of Roman glass. I was blown away (so to speak) by the iridescence of their surfaces.
I was more than a little disappointed to learn that the iridescence was not intentional nor an effect created by Roman artisanship. Instead, it’s the result of corrosion. But a recent study and article makes me realize how cool that corrosive effect is. As the article says,
Nature is the ultimate nanofabricator.
The study examines a fragment nick-named the “wow glass” (not pictured here).
As the article explains, colors in this (and other Roman glass and some organic occurrences such as butterfly-wings and beetle-shells)
don’t come from any pigment molecules but from how they are structured.
And this has implications for materials science and practical applications. The whole article over at Ars Technica is a fascinating read that I’d highly recommend.