Hydrowoodwardite is a rare copper aluminum sulfate mineral typically found as a secondary product in oxidized copper deposits. Collectors usually look for its distinctive pale blue to blue-green platy crusts or radial crystal sprays often coating other copper minerals.
Is this hydrowoodwardite?
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 hydrowoodwardite with a known reference. Hydrowoodwardite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hydrowoodwardite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Hydrowoodwardite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: blue, pale blue, blue-green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts, radial aggregates.
Often confused with
Hydrowoodwardite vs. its common look-alikes, and how to tell them apart in the field.


How to tell apart: Streak differs, so Hydrowoodwardite leaves white, Cyanotrichite leaves pale blue; luster reads pearly on Hydrowoodwardite and silky on Cyanotrichite.

How to tell apart: Streak differs, so Hydrowoodwardite leaves white, Langite leaves pale blue; luster reads pearly on Hydrowoodwardite and vitreous on Langite.
Often found alongside hydrowoodwardite
Minerals reported to co-occur with hydrowoodwardite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- [Cu₁₋ₓAlₓ(OH)₂][(SO₄)ₓ/₂·nH₂O]
- Mohs hardness
- 2
- Density
- 2.0-2.2 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy Crystals, Crusts, Radial Aggregates
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Hydrothermal Copper Deposits
- Typical price
- $20-150 per specimen depending on matrix quality
Where rockhounds find hydrowoodwardite
Classic worldwide localities
- Lavrion, Greece
- Brixlegg, Austria
- Cap Garonne, France
- Rudabánya, Hungary
Field-hunting tip
Look in oxidized hydrothermal copper deposits country, the host setting where hydrowoodwardite typically forms. If you start seeing brochantite, posnjakite, chrysocolla in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.




