Brown sapphire is a gem-quality variety of the mineral corundum, known for its extreme hardness and high refractive index. It occurs most frequently as barrel-shaped hexagonal crystals or in alluvial deposits weathered from primary metamorphic or igneous rocks. While less popular than blue or yellow varieties, it is highly valued by collectors for its durability and often striking deep, earthy undertones.
Is this brown sapphire?
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 brown sapphire with a known reference. Brown Sapphire sits at Mohs 9 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Brown Sapphire leaves a none streak.
- 3Read the lusterHold the specimen under a strong light. Brown Sapphire typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, golden brown, reddish brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic crystals, bipyramidal crystals.
Often confused with
Brown Sapphire vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Brown Sapphire is noticeably harder (Mohs 9 vs. 7.5); streak differs — Brown Sapphire leaves none, Zircon leaves white; luster reads vitreous on Brown Sapphire and adamantine on Zircon.
How to tell apart: Brown Sapphire is noticeably harder (Mohs 9 vs. 7-7.5); streak differs — Brown Sapphire leaves none, Tourmaline leaves white.
How to tell apart: Brown Sapphire is noticeably harder (Mohs 9 vs. 8); streak differs — Brown Sapphire leaves none, Topaz leaves white.
Often found alongside brown sapphire
Minerals reported to co-occur with brown sapphire. 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
- 3.98-4.10 g/cm³
- Streak
- None
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Prismatic Crystals, Bipyramidal Crystals
- Cleavage
- None
- Rarity
- Common
- Uses
- Gemstone, Jewelry, Collector
- Host rock
- Pegmatites, Metamorphic Marble, Alluvial Gravels
- Typical price
- $10-100 per carat for commercial quality
Where rockhounds find brown sapphire
1 mapped spotsClassic worldwide localities
- Sri Lanka
- Madagascar
- Tanzania
- Australia
- Thailand
Field-hunting tip
Look in pegmatites, metamorphic marble, alluvial gravels country — that is the host setting where brown sapphire typically forms. If you start seeing spinel, garnet, zircon in float, you are in the right ground. Field specimens usually show a prismatic crystals, bipyramidal crystals habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Indiana — start trip planning there.
Common questions
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Find brown sapphire on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
