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. White Corundum typically shows a vitreous luster.
- 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.
How to tell apart: White Corundum is noticeably harder (Mohs 9 vs. 8).
How to tell apart: White Corundum is noticeably harder (Mohs 9 vs. 7).
How to tell apart: White Corundum is noticeably harder (Mohs 9 vs. 7.5); luster reads vitreous on White Corundum and adamantine on Zircon.
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
- Typical price
- $20-200 per gram depending on clarity and quality
Where rockhounds find white corundum
1 mapped spotsClassic worldwide localities
- Sri Lanka
- Myanmar
- Madagascar
- Tanzania
- USA
Field-hunting tip
Look in metamorphic rocks like marble and gneiss, or igneous pegmatites country, the host setting where white corundum typically forms. If you start seeing spinel, garnet, feldspar in float, you are in the right ground. Field specimens usually show a hexagonal prisms and tabular crystals habit, so 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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Find white corundum on the map
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