Reddingite is a rare phosphate mineral typically found in phosphate-rich zones of granite pegmatites. It forms short, blocky, prismatic crystals or compact granular masses that are prized by advanced collectors of phosphate minerals.

Hardness

3-3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareReddingite Group family

Reddingite

Hardness: 3-3.5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this reddingite?

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 reddingite with a known reference. Reddingite sits at Mohs 3-3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Reddingite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Reddingite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: pink, brownish-pink, yellowish-white, brown.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: short prismatic crystals, granular masses.

Often confused with

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

Often found alongside reddingite

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

All properties

Chemical formula: Mn²⁺₃(PO₄)₂·3H₂O
Mohs hardness: 3-3.5
Density: 3.1-3.2 g/cm³
Colors: Pink Brownish-pink Yellowish-white Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Short Prismatic Crystals, Granular Masses
Cleavage: Distinct On {100}
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $20-200 per specimen

Where rockhounds find reddingite

Classic worldwide localities

Branchville, Connecticut, USA
Poland, Maine, USA
Hagendorf, Bavaria, Germany
Rapid Creek, Yukon, Canada

Field-hunting tip

Look in granite pegmatites country — that is the host setting where reddingite typically forms. If you start seeing triphylite, eosphorite, dickinsonite in float, you are in the right ground. Field specimens usually show a short prismatic crystals, granular masses habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify reddingite?+

Mohs hardness is 3-3.5. It typically shows a vitreous luster. The streak is white. Common colors include pink, brownish-pink, yellowish-white, brown.

Where is reddingite found?+

Notable localities include Branchville, Connecticut, USA; Poland, Maine, USA; Hagendorf, Bavaria, Germany; Rapid Creek, Yukon, Canada.

How much is reddingite worth?+

Typical asking prices fall in the range of $20-200 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like reddingite?+

Reddingite is most often confused with Phosphosiderite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with reddingite?+

Reddingite commonly co-occurs with Triphylite, Eosphorite, Dickinsonite, Apatite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does reddingite form in?+

Reddingite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is reddingite used for?+

Reddingite is used in collector.

Find reddingite on the map

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