Schairerite is a very rare sulfate mineral found almost exclusively in the extreme evaporite environments of Searles Lake, California. It typically forms sharp, transparent to translucent rhombohedral crystals that may be colorless or show a faint yellow tint. Due to its solubility in water, it must be stored in a dry, airtight environment to prevent dissolution or dehydration.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent with clay inclusions

mineralrare

Schairerite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent with clay inclusions

No image

Is this schairerite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch schairerite with a known reference. Schairerite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: colorless.
5
Look at form & habit
Crystal system: trigonal. Typical habit: rhombohedral crystals.

Often confused with

Schairerite vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside schairerite

Minerals reported to co-occur with schairerite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Na₂₁(SO₄)₇ClF₆
Mohs hardness: 3.5
Density: 2.612-2.616 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent with clay inclusions
Crystal system: Trigonal
Crystal habit: Rhombohedral crystals
Cleavage: Indistinct
Rarity: Rare
Uses: Collector
Host rock: In a playa lake deposit (Searles Lake, California, USA); associated with an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada)

Where rockhounds find schairerite

Classic worldwide localities

Searles Lake, San Bernardino Co., California, USA
Mont Saint-Hilare, Quebec, Canada
Nagyvisnyó evaporite deposit, Bükk Mountains, Hungary

Field-hunting tip

Where it forms: In a playa lake deposit (Searles Lake, California, USA); associated with an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada). If you start seeing galeite, gaylussite, tychite in float, you are in the right ground. Typical habit: rhombohedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify schairerite?+

Mohs hardness is 3.5. Luster: vitreous. The streak is white. Common colors include colorless.

Where is schairerite found?+

Notable localities include Searles Lake, San Bernardino Co., California, USA; Mont Saint-Hilare, Quebec, Canada; Nagyvisnyó evaporite deposit, Bükk Mountains, Hungary.

What rocks look like schairerite?+

Schairerite is most often confused with Northupite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with schairerite?+

Schairerite commonly co-occurs with Galeite, Gaylussite, Tychite, Pirssonite, Thénardite, Northupite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does schairerite form in?+

Where it forms: In a playa lake deposit (Searles Lake, California, USA); associated with an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada). Working float back to the host body is the standard way to chase a fresh occurrence.

What is schairerite used for?+

Schairerite is used in collector.

Find schairerite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.