Thin film crystals
Thin film crystals formed by evaporation of a solution in which the solute was a mixture iron, aluminum, phosphorus, and ammonium sulfates. Solution was smeared on a glass slide, and the nulceation site in the center was likely a dust particle. Polarized light microscopy with color introduced by a waveplate.
Submitted by: Karl Gaff, K Gaff Microscopy, Dublin, Ireland