Kalistrontite is a rare potassium-strontium sulfate primarily found in saline evaporite deposits. Collectors should look for its characteristic tabular crystal habit or white crusts, often associated with other salt minerals like halite and sylvite.

Hardness

2-2.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Kalistrontite

Hardness: 2-2.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this kalistrontite?

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 kalistrontite with a known reference. Kalistrontite sits at Mohs 2-2.5, 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: tabular crystals, massive, crusts.

Often confused with

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

Often found alongside kalistrontite

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

All properties

Chemical formula: K₂Sr(SO₄)₂
Mohs hardness: 2-2.5
Density: 3.30 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Tabular crystals, massive, crusts
Cleavage: On {0001}, perfect
Rarity: Rare
Uses: Collector
Host rock: In a drillhole into anhydrite beds, probably formed by the reaction of sylvite with strontium-bearing solutions (Alshtan, Russia); an alteration product of celestine (Pleismar, Germany)

Where rockhounds find kalistrontite

Classic worldwide localities

Alshtan, Sterlitamak district, southwestern Ural Mountains, Russia
Bohrung, near Pleismar, Saxony-Anhalt, and from Kalkberg, near Lüneburg, Lower Saxony, Germany
Stebnyk, Ukraine
Cesano geothermal field, Latium, Italy
Omongwa Pan, southwestern Kalahari, Namibia

Field-hunting tip

Where it forms: In a drillhole into anhydrite beds, probably formed by the reaction of sylvite with strontium-bearing solutions (Alshtan, Russia); an alteration product of celestine (Pleismar, Germany). If you start seeing halite, anhydrite, dolomite in float, you are in the right ground. Typical habit: tabular crystals, massive, crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kalistrontite?+

Mohs hardness is 2-2.5. Luster: vitreous. The streak is white. Common colors include colorless.

Where is kalistrontite found?+

Notable localities include Alshtan, Sterlitamak district, southwestern Ural Mountains, Russia; Bohrung, near Pleismar, Saxony-Anhalt, and from Kalkberg, near Lüneburg, Lower Saxony, Germany; Stebnyk, Ukraine; Cesano geothermal field, Latium, Italy; Omongwa Pan, southwestern Kalahari, Namibia.

What rocks look like kalistrontite?+

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

What minerals are found with kalistrontite?+

Kalistrontite commonly co-occurs with Halite, Anhydrite, Dolomite, Sylvite, Clay, Gypsum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kalistrontite form in?+

Where it forms: In a drillhole into anhydrite beds, probably formed by the reaction of sylvite with strontium-bearing solutions (Alshtan, Russia); an alteration product of celestine (Pleismar, Germany). Working float back to the host body is the standard way to chase a fresh occurrence.

What is kalistrontite used for?+

Kalistrontite is used in collector.

Find kalistrontite on the map

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