Strontiopharmacosiderite is a rare member of the pharmacosiderite group, characterized by its distinct cubic habit and yellowish hues. It is a secondary mineral typically found in the gossan zones of arsenic-rich hydrothermal deposits, often occurring as small pseudocubic crystals. Due to its arsenic content, collectors should exercise caution during handling and storage.
Is this strontiopharmacosiderite?
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 strontiopharmacosiderite with a known reference. Strontiopharmacosiderite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Strontiopharmacosiderite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Strontiopharmacosiderite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, greenish-yellow, yellowish-brown.
- 5Look at form & habitCrystal system: cubic. Typical habit: pseudocubic crystals, granular aggregates.
Often confused with
Strontiopharmacosiderite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Strontiopharmacosiderite leaves yellow, Pharmacosiderite leaves white; luster reads vitreous on Strontiopharmacosiderite and adamantine on Pharmacosiderite.
How to tell apart: Scorodite is the harder of the two (Mohs 3.5-4 vs. 2.5); streak differs, so Strontiopharmacosiderite leaves yellow, Scorodite leaves white; luster reads vitreous on Strontiopharmacosiderite and vitreous to sub-adamantine on Scorodite.
Often found alongside strontiopharmacosiderite
Minerals reported to co-occur with strontiopharmacosiderite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SrFe₄(AsO₄)₃(OH)₅·5H₂O
- Mohs hardness
- 2.5
- Density
- 2.88 g/cm³
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Cubic
- Crystal habit
- Pseudocubic Crystals, Granular Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Arsenic-rich Hydrothermal Mineral Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find strontiopharmacosiderite
Classic worldwide localities
- Kurnakovsky deposit, Russia
- San Telmo mine, Spain
- Wheal Gorland, United Kingdom
Field-hunting tip
Look in oxidized zones of arsenic-rich hydrothermal mineral deposits country, the host setting where strontiopharmacosiderite typically forms. If you start seeing arsenopyrite, goethite, limonite in float, you are in the right ground. Field specimens usually show a pseudocubic crystals, granular aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify strontiopharmacosiderite?+
Where is strontiopharmacosiderite found?+
How much is strontiopharmacosiderite worth?+
Is strontiopharmacosiderite safe to handle?+
What rocks look like strontiopharmacosiderite?+
What minerals are found with strontiopharmacosiderite?+
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Find strontiopharmacosiderite on the map
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