Glauberite is a soluble sulfate mineral that typically forms as wedge-shaped, tabular crystals within evaporite sequences. It is notably unstable in water, where it may alter to gypsum or other sulfate minerals, making it a challenging species to preserve in humid environments. Look for its characteristic thin, platy crystal habits in saline lake deposits.
Is this glauberite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch glauberite with a known reference. Glauberite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to waxy, pearly on {001} cleavage surfaces.
- 4Match the color rangeCompare against the expected color range: colorless, gray, gray white, yellow, yellowish white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic, tabular.
Often confused with
Glauberite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads vitreous to waxy, pearly on {001} cleavage surfaces on Glauberite and subvitreous, pearly on {010} cleavages, silky if fibrous on Gypsum.
How to tell apart: Luster reads vitreous to waxy, pearly on {001} cleavage surfaces on Glauberite and pearly on {010}, vitreous to greasy on {001}; vitreous on {100} on Anhydrite.
Often found alongside glauberite
Minerals reported to co-occur with glauberite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Ca(SO₄)₂
- Mohs hardness
- 2.5-3
- Density
- 2.75-2.85 g/cm³
- Streak
- White
- Luster
- Vitreous to waxy, pearly on {001} cleavage surfaces
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic, tabular
- Cleavage
- {001}, perfect; {110}, imperfect
- Rarity
- Common
- Uses
- Collector, Industrial source of sodium sulfate
- Host rock
- A common constituent of continental and marine evaporite deposits; as sublimates around fumaroles; in mineral-filled cavities in basaltic lava; in nitrate deposits in arid climates
Where rockhounds find glauberite
5 mapped spotsClassic worldwide localities
- Searles Lake, San Bernardino Co., Borax Lake, Lake Co., and the Salton Sea, Imperial Co., California, USA
- Ector and Upton Cos., Texas and Eddy Co., New Mexico, USA
- Camp Verde, Yavapai Co., Arizona, USA
- Great Salt Lake, Davis Co., Utah, USA
- Villarrubia de Santiago, near Ocaña, Toledo Province, Spain
- Douglashall, near Westeregeln, Saxony-Anhalt, Germany
Field-hunting tip
Where it forms: A common constituent of continental and marine evaporite deposits; as sublimates around fumaroles; in mineral-filled cavities in basaltic lava; in nitrate deposits in arid climates. If you start seeing halite, polyhalite, anhydrite in float, you are in the right ground. Typical habit: prismatic, tabular. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, New Mexico, North Dakota. Start trip planning there.
Common questions
How do you identify glauberite?+
Where is glauberite found?+
Can I find glauberite in the United States?+
What rocks look like glauberite?+
What minerals are found with glauberite?+
What kind of rock does glauberite form in?+
What is glauberite used for?+
Find glauberite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
