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Photographic gallery.  Thousands of particles under the microscope.
Microcrystal Test for Sulfur or Calcium

Calcium Sulfate Dihydrate

This is a calcium sulfate percipitate formed by the addition of dilute sulfuric acid to a solution containing calcium chloride. In this case the test drop was very concentrated. For more typical crystals look under "Chemical Microscopy"

Transmitted Off Crossed Circular Polarized Light


Significance in the Environment:

Characteristic Features:

Associated Particles:


Chamot, Emile Monnin and Clyde Walter Mason, HANDBOOK OF CHEMICAL MICROSCOPY, Volume II, pp. 105-107 and 349-350, 1940.