Sodium Phosphate Microcrystal Test for Magnesium
The material suspected of containing magnesium may be taken into solution as the chloride. To this neutral solution add a
few crystals of ammonium chloride and citric acid. After this is dissolved add a drop of concentrated sodium phosphate
(HNaPO4). Now cause a drop of concentrated ammonium hydroxide to flow into the test drop. The initial reaction
is granular but characteristic crystals soon form.