Johnwalkite is a rare phosphate mineral typically found in complex granite pegmatites. It usually forms small, yellowish-brown tabular crystals and is highly sought after by systematic mineral collectors due to its scarcity.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareJohnwalkite Group family

Johnwalkite

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

Is this johnwalkite?

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 johnwalkite with a known reference. Johnwalkite sits at Mohs 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. Johnwalkite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Johnwalkite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular to blocky crystals.

Often confused with

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

Often found alongside johnwalkite

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

All properties

Chemical formula: K₂Mn²⁺₄Nb₂O₂[(PO₄)₄]·4H₂O
Mohs hardness: 3.5
Density: 3.54 g/cm³
Colors: Yellow Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Tabular to Blocky Crystals
Cleavage: Distinct On {100}
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find johnwalkite

Classic worldwide localities

Tip Top mine, South Dakota, USA
Mangualde mine, Portugal

Field-hunting tip

Look in granite pegmatites country, the host setting where johnwalkite typically forms. If you start seeing apatite, quartz, muscovite in float, you are in the right ground. Field specimens usually show a tabular to blocky crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify johnwalkite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, brown.

Where is johnwalkite found?+

Notable localities include Tip Top mine, South Dakota, USA; Mangualde mine, Portugal.

How much is johnwalkite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like johnwalkite?+

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

What minerals are found with johnwalkite?+

Johnwalkite commonly co-occurs with Apatite, Quartz, Muscovite, Microcline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does johnwalkite form in?+

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

What is johnwalkite used for?+

Johnwalkite is used in collector.

Find johnwalkite on the map

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