White Corundum, also known as Leucosapphire, is the colorless variety of the mineral species corundum. It is characterized by its extreme hardness and high density, often found as hexagonal barrel-shaped crystals in metamorphic marble deposits or alluvial gravels.
Is this white corundum?
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 white corundum with a known reference. White Corundum sits at Mohs 9, 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: white, colorless.
- 4Look at form & habitCrystal system: trigonal. Typical habit: hexagonal prisms and tabular crystals.
Often confused with
White Corundum vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside white corundum
Minerals reported to co-occur with white corundum. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₂O₃
- Mohs hardness
- 9
- Density
- 4.02 g/cm³
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Hexagonal prisms and tabular crystals
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector, Abrasive, Gemstone
- Host rock
- metamorphic rocks like marble and gneiss, or igneous pegmatites
Where rockhounds find white corundum
1 mapped spotsClassic worldwide localities
- Sri Lanka
- Myanmar
- Madagascar
- Tanzania
- USA
Field-hunting tip
Where it forms: metamorphic rocks like marble and gneiss, or igneous pegmatites. If you start seeing spinel, garnet, feldspar in float, you are in the right ground. Typical habit: hexagonal prisms and tabular crystals. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New York. Start trip planning there.
More white corundum photos
Common questions
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What rocks look like white corundum?+
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Find white corundum on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
