Zirklerite is a rare magnesium-aluminum chloride hydroxide typically found in evaporite salt deposits. It is known primarily from the Wathlingen potash mines in Germany, where it occurs as delicate tabular crystals or massive aggregates. Collectors value it for its unusual chemical composition and limited locality availability.
Is this zirklerite?
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 zirklerite with a known reference. Zirklerite sits at Mohs ~3.5, 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 dull.
- 4Match the color rangeCompare against the expected color range: light gray, white.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: massive.
Often confused with
Zirklerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Talmessite is the harder of the two (Mohs 5 vs. ~3.5).
How to tell apart: Zirklerite is noticeably harder (Mohs ~3.5 vs. 2.5); luster reads vitreous to dull on Zirklerite and waxy, pearly on cleavage surfaces on Brucite.
Often found alongside zirklerite
Minerals reported to co-occur with zirklerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe,Mg)₉Al₄Cl₁₈(OH)₁₂·14H₂O
- Mohs hardness
- ~3.5
- Density
- 2.6 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous to dull
- Transparency
- Semitransparent
- Crystal system
- Hexagonal
- Crystal habit
- Massive
- Cleavage
- Rhombohedral
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As the principal constituent of a rock composed of halite, anhydrite, quartz, and clay minerals, in brecciated layers intercalcated with halite and potash layers
Where rockhounds find zirklerite
Classic worldwide localities
- Adolfsgliick mine, Hope, west of Hamelyn, Lower Saxony, Germany
Field-hunting tip
Where it forms: As the principal constituent of a rock composed of halite, anhydrite, quartz, and clay minerals, in brecciated layers intercalcated with halite and potash layers. If you start seeing halite, anhydrite, rinneite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify zirklerite?+
Where is zirklerite found?+
What rocks look like zirklerite?+
What minerals are found with zirklerite?+
What kind of rock does zirklerite form in?+
What is zirklerite used for?+
Find zirklerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
