Gatedalite is a rare zirconium manganese silicate that forms gray irregularly rounded grains. It occurs in hausmannite-bearing skarn associated with a regionally-metamphosed Mn-Fe deposit. It was first described from the dump near the New Shaft (Nya Schaktet), Långban, Värmland, Sweden.
Is this gatedalite?
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 gatedalite with a known reference. Gatedalite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Gatedalite leaves a yellowish streak.
- 3Read the lusterHold the specimen under a strong light. Gatedalite typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: gray.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: irregularly rounded grains.
Often confused with
Gatedalite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Gatedalite leaves yellowish, Finnemanite leaves white; luster reads submetallic on Gatedalite and subadamantine on Finnemanite.
How to tell apart: Streak differs, so Gatedalite leaves yellowish, Mimetite leaves white; luster reads submetallic on Gatedalite and resinous to subadamantine on Mimetite.
Often found alongside gatedalite
Minerals reported to co-occur with gatedalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- ZrMn²⁺₂Mn³⁺₄O₈(SiO₄)
- Mohs hardness
- 3.5-4
- Density
- 4.783 g/cm³
- Colors
- Streak
- Yellowish
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Irregularly Rounded Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Iron-manganese Ore Deposits
Where rockhounds find gatedalite
Classic worldwide localities
- Långban mine, Sweden
Field-hunting tip
Look in metamorphosed iron-manganese ore deposits country, the host setting where gatedalite typically forms. If you start seeing långbanite, baryte, hausmannite in float, you are in the right ground. Field specimens usually show a irregularly rounded grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify gatedalite?+
Where is gatedalite found?+
What rocks look like gatedalite?+
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Find gatedalite on the map
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