Mooreite is a rare hydrated manganese-zinc sulfate mineral found almost exclusively in the famous zinc mines of Franklin and Sterling Hill, New Jersey. It typically forms thin, pale yellowish brown tabular crystals or platy masses associated with complex zinc-manganese assemblages in metamorphic rocks.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Mooreite

Hardness: 3
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this mooreite?

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 mooreite with a known reference. Mooreite sits at Mohs 3, 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: colorless, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy, tabular.

Often confused with

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

mineral

Sussexite

Mohs 3-3.5

How to tell apart: Luster reads vitreous on Mooreite and silky, dull, earthy on Sussexite.

How to tell apart: Mooreite is noticeably harder (Mohs 3 vs. ~2); luster reads vitreous on Mooreite and pearly on Brugnatellite.

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Often found alongside mooreite

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

All properties

Chemical formula: Mg₁₅(SO₄)₂(OH)₂₆·8H₂O
Mohs hardness: 3
Density: 2.47 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy, tabular
Cleavage: On {010}, perfect
Rarity: Rare
Uses: Collector
Host rock: Rarely in cavities and veinlets in franklinite–willemite–calcite ore from a metamorphosed stratiform zinc orebody

Where rockhounds find mooreite

Classic worldwide localities

Sterling Hill, Ogdensburg, Sussex Co., New Jersey, USA

Field-hunting tip

Where it forms: Rarely in cavities and veinlets in franklinite–willemite–calcite ore from a metamorphosed stratiform zinc orebody. If you start seeing pyrochroite, rhodochrosite, zincite in float, you are in the right ground. Typical habit: platy, tabular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mooreite?+

Mohs hardness is 3. Luster: vitreous. The streak is white. Common colors include colorless, white.

Where is mooreite found?+

Notable localities include Sterling Hill, Ogdensburg, Sussex Co., New Jersey, USA.

What rocks look like mooreite?+

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

What minerals are found with mooreite?+

Mooreite commonly co-occurs with Pyrochroite, Rhodochrosite, Zincite, Torreyite, Fluoborite, Franklinite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mooreite form in?+

Where it forms: Rarely in cavities and veinlets in franklinite–willemite–calcite ore from a metamorphosed stratiform zinc orebody. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mooreite used for?+

Mooreite is used in collector.

Find mooreite on the map

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