Glauberite Crystals from the
Salt Mine at Camp Verde, AZ. Note that the crystal on the right is
beginning to alter to Gypsum.
THESE IMAGES ARE OF VARIOUS PSEUDOMORPHS AFTER GLAUBERITE.
Calcite Psuedomorphs after Glauberite - The image on the right is looking down the "C" axis of the smaller crystal on the left.
Aragonite Psuedomorphs after Glauberite
Gypsum Pseudomorph after Glauberite
GLAUBERITE PSEUDOMORPHS - Within an ancient lake in the Verde Valley of central Arizona fine grained sediments accumulated. As the arid conditions prevailed Glauberite crystals began to develop and grow within this alkali environment. Many years after the crystals had formed they were dissolved away by peculating aqueous solutions. This left a void that was in the shaped of the Glauberite crystal. Minerals were then deposited within these voids to produce a cast of the previous Glauberite crystal. These casts are the pseudomorphs (pseudo - false, morph - form). They have the shaped of the original Glauberite but are composed of different minerals. Here, in the Verde Valley the substituting minerals are Calcite, Gypsum and Aragonite.
CHEMISTRY - Na2Ca(SO4)2
CRYSTALLOGRAPHY - Monoclinic prismatic
CRYSTAL GROWTH AND HABITS - Glauberite is commonly found as prismatic to tabular crystals often with striated faces. It also form granular to massive layers.
COLOR AND OPTICAL PROPERTIES - Glauberite is most commonly gray to slightly yellowish in color. It is transparent to translucent.
HARDNESS - 2.5 - 3
SPECIFIC GRAVITY - 2.75 - 2.85
LUSTER - Waxy to sub vitreous
STREAK - White
BREAKABILITY - Glauberite has a perfect cleavage along {001} and poor along {110}, with a conchoidal fracture. It is brittle.
OTHER - Glauberite has a slightly saline taste. In the presence of water it will develop a white coating of Gypsum.
OCCURRENCE - Found in saline deposits as an evaporite mineral of marine or lacustrine origin.
ASSOCIATED MINERALS - Halite, Polyhalite, Anhydrite, Thenardite, Gypsum and Mirabilite.
MINERAL NAME - The name is in reference to the German Chemist Rudolf Glauber who is associated with "Glauber's Salt" (Na2SO4) of which Glauberite contains in abundance.