Sulphohalite is a rare sulfate-halide mineral found primarily in arid, high-salinity evaporite environments. Collectors look for its characteristic sharp, dodecahedral crystals often associated with halite and other alkaline salts in dried lake beds.

Hardness

~3.5

Mohs

Luster

Vitreous to greasy

Streak

White

Transparency

Transparent

mineralrare

Sulphohalite

Hardness: ~3.5
Luster: Vitreous to greasy
Streak: White
Transparency: Transparent

Is this sulphohalite?

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 sulphohalite with a known reference. Sulphohalite 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 to greasy.
4
Match the color range
Compare against the expected color range: colorless, green yellow, gray, grayish yellow, light green yellow.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals.

Often confused with

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

mineral

Halite

Mohs 2-2.5

How to tell apart: Sulphohalite is noticeably harder (Mohs ~3.5 vs. 2-2.5).

Often found alongside sulphohalite

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

All properties

Chemical formula: Na₆(SO₄)₂FCl
Mohs hardness: ~3.5
Density: 2.489-2.500 g/cm³
Colors: Colorless Green yellow Gray Grayish yellowLight green yellow
Streak: White
Luster: Vitreous to greasy
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Octahedral crystals
Cleavage: Perfect
Fluorescence: Bright white to creamy white under LW UV
Rarity: Rare
Uses: Collector
Host rock: In evaporite deposits (Searles Lake, California, USA; Otjiwalundo salt pan, Namibia); a volcanic sublimate (Kamchatka Peninsula, Russia)

Where rockhounds find sulphohalite

Classic worldwide localities

Searles Lake, San Bernardino Co., California, USA
Otjiwalundo salt pan, about 400 km west-northwest of Otavi, Namibia
Volcanoes on the Kamchatka Peninsula, Russia

Field-hunting tip

Where it forms: In evaporite deposits (Searles Lake, California, USA; Otjiwalundo salt pan, Namibia); a volcanic sublimate (Kamchatka Peninsula, Russia). If you start seeing hanksite, halite, trona in float, you are in the right ground. Typical habit: octahedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify sulphohalite?+

Mohs hardness is ~3.5. Luster: vitreous to greasy. The streak is white. Common colors include colorless, green yellow, gray, grayish yellow.

Where is sulphohalite found?+

Notable localities include Searles Lake, San Bernardino Co., California, USA; Otjiwalundo salt pan, about 400 km west-northwest of Otavi, Namibia; Volcanoes on the Kamchatka Peninsula, Russia.

What rocks look like sulphohalite?+

Sulphohalite is most often confused with Halite, Thénardite, Aphthitalite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with sulphohalite?+

Sulphohalite commonly co-occurs with Hanksite, Halite, Trona, Thénardite, Pirssonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does sulphohalite form in?+

Where it forms: In evaporite deposits (Searles Lake, California, USA; Otjiwalundo salt pan, Namibia); a volcanic sublimate (Kamchatka Peninsula, Russia). Working float back to the host body is the standard way to chase a fresh occurrence.

What is sulphohalite used for?+

Sulphohalite is used in collector.

Find sulphohalite on the map

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