Rongibbsite is a rare secondary lead-aluminum silicate mineral found in oxidized base metal deposits. It typically occurs as small, colorless, platy or micaceous crystals often associated with other lead-bearing minerals in hydrothermal environments.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Rongibbsite

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

Is this rongibbsite?

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 rongibbsite with a known reference. Rongibbsite 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. Rongibbsite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Rongibbsite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals.

Often confused with

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

How to tell apart: Luster reads vitreous on Rongibbsite and vitreous to resinous to dull on Plumbogummite.

Compare →

Often found alongside rongibbsite

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

All properties

Chemical formula: Pb₂Al₂Si₂O₁₀(OH)₄
Mohs hardness: 3.5
Density: 4.43 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy Crystals
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Hydrothermal Lead-zinc Deposits

Where rockhounds find rongibbsite

Classic worldwide localities

Rongibbs mine, Arizona, USA

Field-hunting tip

Look in oxidized hydrothermal lead-zinc deposits country, the host setting where rongibbsite typically forms. If you start seeing quartz, cerussite, wulfenite in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify rongibbsite?+

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

Where is rongibbsite found?+

Notable localities include Rongibbs mine, Arizona, USA.

Is rongibbsite safe to handle?+

It contains toxic constituents. Contains lead; wash hands thoroughly after handling and avoid inhaling dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like rongibbsite?+

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

What minerals are found with rongibbsite?+

Rongibbsite commonly co-occurs with Quartz, Cerussite, Wulfenite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does rongibbsite form in?+

Rongibbsite typically forms in oxidized hydrothermal lead-zinc deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is rongibbsite used for?+

Rongibbsite is used in collector.

Find rongibbsite on the map

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