Diatome stack

[Radazz]

I saw an example of diatomes photographed in darkfield, and had to try myself.
I got out a slide of diatomes from Diatom Shop by Stephano. Darkfield looked really nice, and I will have to get some shots soon.
I tried a few other lighting methods, but phase contrast brought out lots of colors and beauty which I also need to get some images
Back to this one, there was one diatom on the slide which was opaque under all conditions. Phase contrast showed more of the surface than anything else, but at 40x, rolling the focus, I still couldn't really see what the shape was.
So I did a 20 shot stack and got this result. Still don't know what it is, but the horns are interesting.
Nikon Optiphot 40x ph3

[Charles]

Usually Stephano identifies most of his diatoms on the slide label. It's a bit dark but, this one looks like an Oamaru diatom called Aulacodiscus, probably amoenus or nova-zealandicus.