Pieczkaite is a rare manganese-dominant member of the apatite group characterized by its distinct yellow to brownish prismatic crystals. It is primarily found in granite pegmatites and is highly sought after by mineral collectors due to its rarity and specific chemical composition.

Hardness

4-5

Mohs

Streak

Grayish white

Transparency

Transparent

mineralrareApatite Group family

Pieczkaite

Hardness: 4-5
Streak: Grayish white
Transparency: Transparent

No image

Is this pieczkaite?

4-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 pieczkaite with a known reference. Pieczkaite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: grayish white.
3
Match the color range
Compare against the expected color range: gray.
4
Look at form & habit
Crystal system: hexagonal. Typical habit: prismatic crystals.

Often confused with

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

mineral

Apatite

Mohs 5

How to tell apart: Streak differs, so Pieczkaite leaves grayish white, Apatite leaves white.

How to tell apart: Streak differs, so Pieczkaite leaves grayish white, Triplite leaves white to brown.

Compare →

Often found alongside pieczkaite

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

All properties

Chemical formula: Mn₅(PO₄)₃Cl
Mohs hardness: 4-5
Density: 3.783 g/cm³
Colors: Gray
Streak: Grayish white
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Prismatic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: As small patches and narrow veins in apatite and (Mn,Cl)-bearing apatite in phosphate pods in the interior wall zone of the quartz core of a granitic pegmatite

Where rockhounds find pieczkaite

Classic worldwide localities

Pegmatite no. 22, southeastern shoreline of an unnamed island in Cross Lake, Manitoba, Canada

Field-hunting tip

Where it forms: As small patches and narrow veins in apatite and (Mn,Cl)-bearing apatite in phosphate pods in the interior wall zone of the quartz core of a granitic pegmatite. If you start seeing fluorapatite, manitobaite, eosphorite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify pieczkaite?+

Mohs hardness is 4-5. The streak is grayish white. Common colors include gray.

Where is pieczkaite found?+

Notable localities include Pegmatite no. 22, southeastern shoreline of an unnamed island in Cross Lake, Manitoba, Canada.

What rocks look like pieczkaite?+

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

What minerals are found with pieczkaite?+

Pieczkaite commonly co-occurs with Fluorapatite, Manitobaite, Eosphorite, Triploidite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pieczkaite form in?+

Where it forms: As small patches and narrow veins in apatite and (Mn,Cl)-bearing apatite in phosphate pods in the interior wall zone of the quartz core of a granitic pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pieczkaite used for?+

Pieczkaite is used in collector.

Find pieczkaite on the map

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