Mammothite is a rare lead-copper sulfate-carbonate mineral typically found as small, thin, platy crystals. It is a secondary mineral primarily sourced from the historic oxidized zones of lead-copper mines like those in Tiger, Arizona. Collectors prize it for its rarity and its association with other colorful secondary lead minerals.
Is this mammothite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch mammothite with a known reference. Mammothite sits at Mohs ~3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: bright blue, greenish blue, pale blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, microscopic crystals, tabular.
Often confused with
Mammothite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Mammothite leaves pale blue, Cerussite leaves white; luster reads vitreous on Mammothite and adamantine, tending toward vitreous, resinous on Cerussite.
How to tell apart: Streak differs, so Mammothite leaves pale blue, Anglesite leaves white; luster reads vitreous on Mammothite and adamantine, resinous to vitreous on Anglesite.
Often found alongside mammothite
Minerals reported to co-occur with mammothite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₆Cu₄AlSb⁵⁺O₂(SO₄)₂Cl₄(OH)₁₆
- Mohs hardness
- ~3
- Density
- 5.25 g/cm³
- Streak
- Pale blue
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, microscopic crystals, tabular
- Cleavage
- Distinct on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral in the oxidized zone of a hydrothermal polymetallic base-metal deposit (Tiger, Arizona, USA); in metallic slag, formed by reaction with ocean water (Laurium, Greece)
Where rockhounds find mammothite
Classic worldwide localities
- Mammoth-St. Anthony mine, Tiger, Pinal Co., Arizona, USA
- Laurium, Greece, in slag
Field-hunting tip
Where it forms: A rare secondary mineral in the oxidized zone of a hydrothermal polymetallic base-metal deposit (Tiger, Arizona, USA); in metallic slag, formed by reaction with ocean water (Laurium, Greece). If you start seeing anglesite, leadhillite, caledonite in float, you are in the right ground. Typical habit: acicular, microscopic crystals, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mammothite?+
Where is mammothite found?+
Is mammothite safe to handle?+
What rocks look like mammothite?+
What minerals are found with mammothite?+
What kind of rock does mammothite form in?+
What is mammothite used for?+
Find mammothite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
