Greifensteinite is a rare phosphate mineral characterized by its attractive pale green to brownish-green color and bladed habit. It is found primarily in granite pegmatites and is often associated with other rare phosphate species in complex parageneses. Collectors primarily find it as small, delicate crystal clusters within vugs and cavities in host granite rocks.
Is this greifensteinite?
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 greifensteinite with a known reference. Greifensteinite 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: dark olive green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: aggregates, radial.
Often confused with
Greifensteinite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside greifensteinite
Minerals reported to co-occur with greifensteinite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Fe₅Be₄(PO₄)₆(OH)₄·6H₂O
- Mohs hardness
- 4.5
- Density
- 2.93 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Aggregates, radial
- Cleavage
- Good on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In miarolitic cavities in Li-rich granite pegmatite
Where rockhounds find greifensteinite
Classic worldwide localities
- Tip Top mine, Custer County, South Dakota, USA
- Greifenstein, Saxony, Germany
- João Teodoro mine, Linópolis district, Divino das Laranjeiras, and the Xanda mine, Virgem da Lapa, Minas Gerais, Brazil
Field-hunting tip
Where it forms: In miarolitic cavities in Li-rich granite pegmatite. If you start seeing albite, k-feldspar, roscherite in float, you are in the right ground. Typical habit: aggregates, radial. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify greifensteinite?+
Where is greifensteinite found?+
Is greifensteinite safe to handle?+
What rocks look like greifensteinite?+
What minerals are found with greifensteinite?+
What kind of rock does greifensteinite form in?+
What is greifensteinite used for?+
Find greifensteinite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
