Many Glauberite specimens in collections are not truly Glauberite, but rather other minerals that formed a pseudomorph or epimorph over the Glauberite. Glauberite itself is in fact a rare and unstable mineral, but its remnants and castings are much more prevalent. This is evident by an abundance of empty casts and pseudomorphs found in localities where little or no Glauberite was ever found. There are some localities where hollow Glauberite crystal casts can be found in a rock or mineral base with the original Glauberite completely dissolved.
Glauberite forms in evaporite and clay deposits. These environments enable a crystal to grow without interference from attached matter, so crystals can be perfect on all sides. Such crystals are known as floater crystals.
Some Glauberite pseudomorphs from Camp Verde, Arizona, exhibit a deep green color. These are not natural and have been artificially dyed by certain dealers, thus the buyer should be aware.
True Glauberite does not keep well in collections for it is efflorescent, developing white powder on its surface which dulls its luster. To avoid this, specimens should be placed in conditions where this effect is minimal, such as a damp area. Pseudomorphs and epimorphs are stable and don't require extra protection from humidity.
Glauberite is named after the Dutch/German chemist Johann Rudolf Glauber (1604-1668), who discovered sodium sulfate in 1625. Glauber's salt, a powder of sodium sulfate is also named after Glauber.