Strontioperloffite is a rare phosphate mineral found in phosphate-rich pegmatites, typically occurring as small, dark brown, platy crystals. It is structurally related to the perloffite group and is primarily a target for advanced micromount or systematic mineral collectors.
Is this strontioperloffite?
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 strontioperloffite with a known reference. Strontioperloffite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale orange.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: brownish orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals.
Often confused with
Strontioperloffite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Strontioperloffite leaves pale orange, Perloffite leaves greenish yellow.
How to tell apart: Streak differs, so Strontioperloffite leaves pale orange, Bjarebyite leaves white; luster reads vitreous on Strontioperloffite and subadamantine on Bjarebyite.
Often found alongside strontioperloffite
Minerals reported to co-occur with strontioperloffite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SrMn²⁺₂Fe³⁺₂(PO₄)₃(OH)₃
- Mohs hardness
- 4.5
- Density
- 3.89 g/cm³
- Colors
- Streak
- Pale orange
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy crystals
- Cleavage
- Excellent on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral in cavities in quartz veins from low-temperature hydrothermal solutions
Where rockhounds find strontioperloffite
Classic worldwide localities
- Tip Top mine, South Dakota, USA
Field-hunting tip
Where it forms: A secondary mineral in cavities in quartz veins from low-temperature hydrothermal solutions. If you start seeing copper, cuprite, mitridatite in float, you are in the right ground. Typical habit: platy crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify strontioperloffite?+
Where is strontioperloffite found?+
What rocks look like strontioperloffite?+
What minerals are found with strontioperloffite?+
What kind of rock does strontioperloffite form in?+
What is strontioperloffite used for?+
Find strontioperloffite on the map
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