Reaphookhillite is a rare hydrated zinc magnesium phosphate mineral found in cave environments. It typically forms delicate, colorless platy crystals associated with other phosphate minerals in host limestone settings.
Hardness
2
Mohs
Luster
Vitreous
Transparency
Transparent
Is this reaphookhillite?
4-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 reaphookhillite with a known reference. Reaphookhillite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 3Match the color rangeCompare against the expected color range: colorless.
- 4Look at form & habitCrystal system: triclinic. Typical habit: platy crystals, crusts.
Often confused with
Reaphookhillite vs. its common look-alikes, and how to tell them apart in the field.
All properties
- Chemical formula
- Zn₂Mg(PO₄)₂(H₂O)₄
- Mohs hardness
- 2
- Density
- 2.8 g/cm³
- Colors
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Platy crystals, crusts
- Rarity
- Rare
- Uses
- Collector
- Host rock
- phosphate-rich cave deposits
Where rockhounds find reaphookhillite
Classic worldwide localities
- Reaphook Hill, South Australia
Field-hunting tip
Where it forms: phosphate-rich cave deposits. If you start seeing martins well, flinders ranges, south australia in float, you are in the right ground. Typical habit: platy crystals, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify reaphookhillite?+
Mohs hardness is 2. Luster: vitreous. Common colors include colorless.
Where is reaphookhillite found?+
Notable localities include Reaphook Hill, South Australia.
What rocks look like reaphookhillite?+
Reaphookhillite is most often confused with Hopeite, Tarbuttite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with reaphookhillite?+
Reaphookhillite commonly co-occurs with Martins Well, Flinders Ranges, South Australia, Australia. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does reaphookhillite form in?+
Where it forms: phosphate-rich cave deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is reaphookhillite used for?+
Reaphookhillite is used in collector.
Find reaphookhillite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
