Glaucocerinite is a rare zinc-copper sulfate mineral typically found as secondary crusts or delicate platy aggregates in oxidized base-metal deposits. It is most famous for its occurrence in the historical mining district of Laurion, where it forms small, eye-catching blue coatings on other secondary minerals.
Is this glaucocerinite?
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 glaucocerinite with a known reference. Glaucocerinite sits at Mohs 1, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Glaucocerinite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Glaucocerinite typically shows a waxy luster.
- 4Match the color rangeCompare against the expected color range: pale blue, sky blue, bluish white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts, lamellar aggregates.
Often confused with
Glaucocerinite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads waxy on Glaucocerinite and pearly on Woodwardite.
How to tell apart: Hydrotalcite is the harder of the two (Mohs 2 vs. 1); luster reads waxy on Glaucocerinite and greasy to waxy on Hydrotalcite.
How to tell apart: Aurichalcite is the harder of the two (Mohs 2 vs. 1); streak differs, so Glaucocerinite leaves white, Aurichalcite leaves pale blue; luster reads waxy on Glaucocerinite and pearly on Aurichalcite.
Often found alongside glaucocerinite
Minerals reported to co-occur with glaucocerinite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Zn,Cu)₆Al₃(SO₄,CO₃)₂(OH)₁₈·12H₂O
- Mohs hardness
- 1
- Density
- 2.4 g/cm³
- Streak
- White
- Luster
- Waxy
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy Crystals, Crusts, Lamellar Aggregates
- Cleavage
- Perfect On {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Ore Deposits in Carbonate Rocks
Where rockhounds find glaucocerinite
Classic worldwide localities
- Laurion, Greece
- Tsumeb, Namibia
- Broken Hill, Australia
Field-hunting tip
Look in oxidized ore deposits in carbonate rocks country, the host setting where glaucocerinite typically forms. If you start seeing smithsonite, azurite, malachite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, lamellar aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify glaucocerinite?+
Where is glaucocerinite found?+
What rocks look like glaucocerinite?+
What minerals are found with glaucocerinite?+
What kind of rock does glaucocerinite form in?+
What is glaucocerinite used for?+
Find glaucocerinite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
