One winter evening I decided to try it for myself. I dissolved vitamin C powder in warm water till I had a fairly concentrated solution. I added a few drops to a microscope slide and lowered a cover slip over the liquid to give a thin even layer. As it cooled crystals soon began to form and I watched the process under low power, fascinating in itself.
I had bought some polarizing filters from ebay for just a few pounds and tried them out. I placed one above the microscope light source over the condenser and the second I rotated above the sample until all light was blocked out. Now I moved the crystals in to view and carefully focused on them. I had seen pictures of the crystals under cross polarized light before but I was still unprepared for what I saw. Colourless crystals had been transformed into blazing multi coloured patterns everywhere I looked. Peacock feathers, firework displays, pyschedelic patterns - so many variations that I took hundreds of photos. Each time I tried it I saw different variations , some on a common theme but all subtely different. My favourites are posted here. Maginifications vary from 40x to 200x.
How does it work? A polarizing filter lets light through vibrating in one direction only. The second filter is oriented so it only lets light through which is vibrating at 90 degrees to the light from the first filter.The scientific term for this setup is cross-polarization So no light gets through. If you place a substance between the two filters which can affect the path of the polarized light rays from the first filter some will get through split down into various wavelengths or colours. Such a substance is Vitamin C and it is said to have birefrigent properties. I am experimenting with other substances and will post my results in the future.
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