Tranforming diatoms into magnesium replicas

[Lou Jost]

One of the biggest challenges for photographing diatoms is their transparency. Some scientists have found a way to put diatoms in magnesium gas which replaces the silica with magnesium, forming an exact replica of the diatom in magnesium!
See minute 36:39 (corrected- thanks Rik)
https://www.youtube.com/watch?v=Yl7tCP8Py1M

[enricosavazzi]

The speaker does say "magnesium replica", but the formula shown in the presentation seems to say that the replica material is magnesium oxide. While metallic magnesium is opaque to VIS (albeit very reflective), magnesium oxide is trasparent from NUV to IR, see https://www.osapublishing.org/josa/abst ... a-25-7-207 . Polycrystalline (and powdered) magnesium oxide is very white, i.e. has a high diffuse reflectance in VIS, and is often used in scientific photography to thinly coat a subject and "remove" its color.

Diatoms have indeed a high potential for use in photonics, and studies of these potential applications have been going on for at least a decade. These very same photonic properties of the diatom frustule are most likely adaptive in increasing the light-collecting efficiency of living diatoms.

[Lou Jost]

That's unfortunate. Thanks for "clearing that up"

The speaker does imply that the same researcher also could transform diatoms into other materials. Maybe some of the others are opaque?

[bralex]

I think he's saying "magnesia" not "magnesium" when he talks about the replica.

[enricosavazzi]

I think he's saying "magnesia" not "magnesium" when he talks about the replica.

That would explain it. Magnesia is magnesium oxide, so he may have said the right thing after all.

[Lou Jost]

I heard what I wanted to hear....