Santanaite is an extremely rare lead chromate mineral found primarily in the oxidized zones of lead mines. It typically occurs as small, straw-yellow tabular crystals or crusts associated with other lead-bearing secondary minerals. Due to its rarity and specific chemical requirements for formation, it is highly prized by advanced mineral collectors.
Is this santanaite?
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 santanaite with a known reference. Santanaite sits at Mohs ~4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: straw yellow.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: tabular crystals, crusts.
Often confused with
Santanaite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Santanaite leaves yellow, Phoenicochroite leaves brick-red to yellowish orange.
How to tell apart: Santanaite is noticeably harder (Mohs ~4 vs. 2.75-3); streak differs, so Santanaite leaves yellow, Wulfenite leaves white; luster reads adamantine on Santanaite and resinous, subadamantine to adamantine on Wulfenite.
Often found alongside santanaite
Minerals reported to co-occur with santanaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₁₁CrO₁₆
- Mohs hardness
- ~4
- Density
- 9.155 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Adamantine
- Transparency
- Semitransparent
- Crystal system
- Hexagonal
- Crystal habit
- Tabular crystals, crusts
- Cleavage
- {0001} and {1120}, very good; {1010}, rare
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An alteration product of galena with other chromium-bearing minerals in an oxidized hydrothermal lead deposit
Where rockhounds find santanaite
Classic worldwide localities
- Santa Ana mine, near Caracoles, Sierra Gorda district, Antofagasta, Chile
Field-hunting tip
Where it forms: An alteration product of galena with other chromium-bearing minerals in an oxidized hydrothermal lead deposit. If you start seeing galena, phoenicochroite, chromatian wulfenite in float, you are in the right ground. Typical habit: tabular crystals, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
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Find santanaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
