Hydroscarbroite is a rare aluminum carbonate mineral typically found as white, chalky, or botryoidal coatings within clay-rich sedimentary environments. It is most easily identified by its soft, porcelain-like appearance and its association with other aluminum-rich secondary minerals in coastal cliff settings.
Is this hydroscarbroite?
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 hydroscarbroite with a known reference. Hydroscarbroite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hydroscarbroite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Hydroscarbroite typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: massive, chalky, or botryoidal crusts.
Often confused with
Hydroscarbroite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hydroscarbroite
Minerals reported to co-occur with hydroscarbroite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₁₄(CO₃)₃(OH)₃₆·n H₂O
- Mohs hardness
- 2-3
- Density
- 2.1-2.2 g/cm³
- Colors
- Streak
- White
- Luster
- Dull
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Massive, Chalky, Or Botryoidal Crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Sedimentary Clay Beds and Fissures in Sandstone
Where rockhounds find hydroscarbroite
Classic worldwide localities
- Scarborough, North Yorkshire, England
- Various clay-rich sedimentary deposits
Field-hunting tip
Look in sedimentary clay beds and fissures in sandstone country, the host setting where hydroscarbroite typically forms. If you start seeing kaolinite, gibbsite, allophane in float, you are in the right ground. Field specimens usually show a massive, chalky, or botryoidal crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hydroscarbroite?+
Where is hydroscarbroite found?+
What rocks look like hydroscarbroite?+
What minerals are found with hydroscarbroite?+
What kind of rock does hydroscarbroite form in?+
What is hydroscarbroite used for?+
Find hydroscarbroite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
