Reynoldsite is a rare lead-manganese chromate mineral typically found as delicate, acicular, radiating sprays of yellow-orange needles. It is primarily known from select oxidized base-metal mines in Arizona, where it occurs alongside other lead-rich secondary minerals.
Is this reynoldsite?
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 reynoldsite with a known reference. Reynoldsite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: dark orange-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: subadamantine.
- 4Match the color rangeCompare against the expected color range: dark orange-brown, black.
- 5Look at form & habitCrystal system: triclinic. Typical habit: acicular crystals, radiating clusters.
Often confused with
Reynoldsite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Reynoldsite is noticeably harder (Mohs 4.5 vs. 2.5-3.5); streak differs, so Reynoldsite leaves dark orange-brown, Phoenicochroite leaves brick-red to yellowish orange; luster reads subadamantine on Reynoldsite and adamantine to resinous, glistening on Phoenicochroite.
How to tell apart: Reynoldsite is noticeably harder (Mohs 4.5 vs. 2.5-3); streak differs, so Reynoldsite leaves dark orange-brown, Vauquelinite leaves greenish to brownish; luster reads subadamantine on Reynoldsite and adamantine to resinous on Vauquelinite.
Often found alongside reynoldsite
Minerals reported to co-occur with reynoldsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂Mn₂O₅(CrO₄)
- Mohs hardness
- 4.5
- Density
- 6.574 g/cm³
- Colors
- Dark orange-brownBlack
- Streak
- Dark orange-brown
- Luster
- Subadamantine
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Acicular crystals, radiating clusters
- Cleavage
- Poor on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral derived by weathering primary minerals including oxides and sulfides in the presence of acidic groundwater
Where rockhounds find reynoldsite
Classic worldwide localities
- Found at the Milford no. 3 mine, Goodsprings district, Nevada, USA
- Blue Bell claims, 11 km west of Baker, San Bernardino County, California, USA., and at the Red Lead mine, Dundas, Tasmania, Australia
Field-hunting tip
Where it forms: A secondary mineral derived by weathering primary minerals including oxides and sulfides in the presence of acidic groundwater. If you start seeing coronadite, fluorite, goethite in float, you are in the right ground. Typical habit: acicular crystals, radiating clusters. Train your eye for that shape before scanning the outcrop.
Common questions
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Find reynoldsite on the map
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