Maxixe (pronounced “mashish”) is a rare variety of beryl with a dark blue color. The blue color develops while the gem material is still within the Earth by exposure to natural radiation. Unfortunately, the blue color gradually fades to a pale brownish color upon exposure to light. If Maxixe loses its color, it can be irradiated in a laboratory, however, the renewed blue color will also fade.

Maxixe can be separated from aquamarine in the following ways:

1) by its pleochroism (the strongest pleochroic color of maxixe is seen when the maxixe crystal is viewed down its c-axis, but in aquamarine the strongest blue color is seen when viewing the crystal perpendicular to the c-axis),

2) by its response under an ultraviolet lamp (some maxixe will glow a greenish color under both short- and long-wave ultraviolet radiation), and,

3) a lack of iron in its chemical composition (The iron content test will not be reliable for specimens of synthetic aquamarine which have received their blue color from cobalt or another chromophore.)

These tests can also be used to separate synthetic maxixe (also known an maxixe-type beryl) from synthetic aquamarine.