A Test on Silurian Corals Stained with Alizarin Red S

I've been slicing up Silurian corals in order to experiment with some histological carbonate staining techniques and analysis, mostly just to have fun following crystal diagenesis, observe morphological changes through coral life/death, mineralogy, etc.. I still have a lot of learning and work to do. This is just a first test using Alizarin Red S diluted with hydrochloric acid. For photos, I used my old Canon PowerShot SX120IS 10MP.




Favosites sp. with Alizarin Red staining.
Bridgeport Quarry, Chicago, IL


Zoom


I need to fix lighting!


Above is an unknown specimen found at Hawthorne Quarry, Cicero, IL. It could be Alveolites sp or possibly a Chaetitid sponge.


Above is another Favosites slice from the same coral, vertical slice. from Bridgeport showing corallites.


Dolomite slice with echinoderm skeletal fragments. From Hawthorne.

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Mostly need to figure out a different lighting set up and timing of staining. These were all stained at the same time and sloppily photographed. Next time will stain just one specimen at a time for better quality and photography. Preparation of thin sections need to be a bit more polished. finer grade. These were polished starting with 50, 80, 150, 220, 400, 800grit. Will try to obtain 1200 or higher, construct light box and use a tripod for better quality pics. Next will try combinations of Alizarin Red S and Potassium ferricyanide. Possibly copper nitrate. Also, I forgot to photograph specimens before staining for my records- oops!



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