Fowlerite is a zinc-rich variety of the mineral rhodonite found primarily in the zinc mines of Franklin, New Jersey. It is highly valued by collectors for its distinct pink color and its association with the unique fluorescent mineral assemblage of the region.

Hardness

5.5-6.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareRhodonite family

Fowlerite

Hardness: 5.5-6.5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this fowlerite?

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 fowlerite with a known reference. Fowlerite sits at Mohs 5.5-6.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: pink, reddish-pink, brownish-pink.
5
Look at form & habit
Crystal system: triclinic. Typical habit: massive, granular, tabular crystals.

Often confused with

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

mineral

Rhodochrosite

Mohs 3.5-4

How to tell apart: Fowlerite is noticeably harder (Mohs 5.5-6.5 vs. 3.5-4).

How to tell apart: Luster reads vitreous on Fowlerite and silky, subvitreous on Pectolite.

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Often found alongside fowlerite

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

All properties

Chemical formula: (Mn,Zn)SiO₃
Mohs hardness: 5.5-6.5
Density: 3.5-3.7 g/cm³
Colors: PinkReddish-pinkBrownish-pink
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Massive, granular, tabular crystals
Cleavage: Perfect in two directions
Rarity: Rare
Uses: Collector, Lapidary
Host rock: metamorphosed zinc ore deposits

Where rockhounds find fowlerite

Classic worldwide localities

Franklin, New Jersey
Sterling Hill, New Jersey

Field-hunting tip

Where it forms: metamorphosed zinc ore deposits. If you start seeing willemite, franklinite, zincite in float, you are in the right ground. Typical habit: massive, granular, tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify fowlerite?+

Mohs hardness is 5.5-6.5. Luster: vitreous. The streak is white. Common colors include pink, reddish-pink, brownish-pink.

Where is fowlerite found?+

Notable localities include Franklin, New Jersey; Sterling Hill, New Jersey.

What rocks look like fowlerite?+

Fowlerite is most often confused with Rhodochrosite, Inesite, Pectolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with fowlerite?+

Fowlerite commonly co-occurs with Willemite, Franklinite, Zincite, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does fowlerite form in?+

Where it forms: metamorphosed zinc ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is fowlerite used for?+

Fowlerite is used in collector, lapidary.

Find fowlerite on the map

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