
1) Sodium mineral
Found on
https://www.crosswordclues.com/clue/glauberite

Glauberite is a monoclinic sodium calcium sulfate mineral with the formula Na2Ca(SO4)2 It was first described in 1808 for material from the El Castellar Mine, Villarrubia de Santiago, Toledo, Castile-La Mancha, Spain. It was named for the extracted Glauber`s salts after the German alchemist Johann Rudolf Glauber (1604–1668). Glauberite often fo....
Found on
http://en.wikipedia.org/wiki/Glauberite

• (n.) A mineral, consisting of the sulphates of soda and lime.
Found on
http://thinkexist.com/dictionary/meaning/glauberite/
Glau'ber·ite noun [ From
Glauber , a German chemist, died 1668: confer French
glaubérite , German
glauberit .]
(Min.) A mineral, consisting of the sulphates of soda and lime.
Found on
http://www.encyclo.co.uk/webster/G/31

Glauberite, named after the 17th century German chemist Glauber, is a bitter salty tasting mineral that dissolves slowly in water. It is a sedimentary mineral formed by the evaporation of saline water. It slowly alters to gypsum when exposed to air. It has the formulae Na2Ca(SO4)2.
Found on
http://www.probertencyclopaedia.com/browse/HG.HTM

a mineral, sodium calcium sulfate, NaCa(SO), often found as a deposit on the beds of salt lakes.
Found on
https://www.infoplease.com/dictionary/glauberite
No exact match found.