Stumpflite is a rare platinum-antimonide mineral typically found as microscopic grains within massive sulfide deposits in ultramafic rocks. It is usually identified through polished section microscopy in laboratory settings due to its small crystal size and affinity for other platinum-group minerals.
Is this stumpflite?
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 stumpflite with a known reference. Stumpflite sits at Mohs 5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: silver white.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: inclusions, microscopic crystals.
Often confused with
Stumpflite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside stumpflite
Minerals reported to co-occur with stumpflite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PtSb
- Mohs hardness
- 5
- Density
- 13.52 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Hexagonal
- Crystal habit
- Inclusions, microscopic crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In platinum concentrates from an ultramafic pipe deposit (Driekop mine, South Africa)
Where rockhounds find stumpflite
Classic worldwide localities
- Driekop mine, on the Merensky Reef, Bushveld complex, Transvaal, South Africa (type locality)
- Nizhni Tagil, Ural Mountains, Russia
- Kelvon Grove prospect, near Fifield, New South Wales, Australia
Field-hunting tip
Where it forms: In platinum concentrates from an ultramafic pipe deposit (Driekop mine, South Africa). If you start seeing geversite, pt–fe alloys in float, you are in the right ground. Typical habit: inclusions, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify stumpflite?+
Where is stumpflite found?+
Is stumpflite safe to handle?+
What rocks look like stumpflite?+
What minerals are found with stumpflite?+
What kind of rock does stumpflite form in?+
What is stumpflite used for?+
Find stumpflite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
