Strengite is an attractive iron phosphate mineral often sought by collectors for its vibrant violet to raspberry-red colors. It typically forms as radiating spherical, botryoidal, or drusy aggregates, and is commonly found in the oxidized zones of iron-rich mineral deposits.

Hardness

3.5-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineraluncommon

Strengite

Hardness: 3.5-4
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this strengite?

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 strengite with a known reference. Strengite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Strengite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Strengite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: red, violet, pink, magenta, colorless.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: botryoidal, crusts, radial aggregates, or prismatic crystals.

Often confused with

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

mineral

Variscite

Mohs 3.5-4.5

How to tell apart: Luster reads vitreous on Strengite and waxy on Variscite.

Often found alongside strengite

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

All properties

Chemical formula: FePO₄·2H₂O
Mohs hardness: 3.5-4
Density: 2.87 g/cm³
Colors: Red Violet Pink Magenta Colorless
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Botryoidal, Crusts, Radial Aggregates, Or Prismatic Crystals
Cleavage: Good On {010}
Rarity: Uncommon
Uses: Collector, Ornamental
Host rock: Phosphate-rich Hydrothermal Veins in Granitic Pegmatites or Secondary Gossans
Typical price: $15-150 thumbnail, $50-500 cabinet specimen

Where rockhounds find strengite

Classic worldwide localities

Pleystein, Germany
Minas Gerais, Brazil
Rockbridge County, Virginia, USA
Yukon Territory, Canada

Field-hunting tip

Look in phosphate-rich hydrothermal veins in granitic pegmatites or secondary gossans country — that is the host setting where strengite typically forms. If you start seeing vivianite, cacoxenite, rockbridgeite in float, you are in the right ground. Field specimens usually show a botryoidal, crusts, radial aggregates, or prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify strengite?+

Mohs hardness is 3.5-4. It typically shows a vitreous luster. The streak is white. Common colors include red, violet, pink, magenta.

Where is strengite found?+

Notable localities include Pleystein, Germany; Minas Gerais, Brazil; Rockbridge County, Virginia, USA; Yukon Territory, Canada.

How much is strengite worth?+

Typical asking prices fall in the range of $15-150 thumbnail, $50-500 cabinet specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like strengite?+

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

What minerals are found with strengite?+

Strengite commonly co-occurs with Vivianite, Cacoxenite, Rockbridgeite, Leucophosphite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does strengite form in?+

Strengite typically forms in phosphate-rich hydrothermal veins in granitic pegmatites or secondary gossans. Working float back to the host body is the standard way to chase a fresh occurrence.

What is strengite used for?+

Strengite is used in collector, ornamental.

Find strengite on the map

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