Tabbyite is a variety of bitumen or asphaltum found primarily in the Uinta Basin of Utah. It is a solid, brittle hydrocarbon that presents as a dark brown to black mass with a distinct resinous luster and often exhibits conchoidal fracture.
Is this tabbyite?
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 tabbyite with a known reference. Tabbyite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Tabbyite leaves a brown streak.
- 3Read the lusterHold the specimen under a strong light. Tabbyite typically shows a resinous luster.
- 4Match the color rangeCompare against the expected color range: black, brown.
- 5Look at form & habitTypical habit: massive.
Often confused with
Tabbyite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads resinous on Tabbyite and bright on Uintaite.
How to tell apart: Tabbyite is noticeably harder (Mohs 2-3 vs. 1); streak differs, so Tabbyite leaves brown, Ozokerite leaves white to yellowish; luster reads resinous on Tabbyite and greasy on Ozokerite.
Often found alongside tabbyite
Minerals reported to co-occur with tabbyite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 2-3
- Density
- 1.05-1.15 g/cm³
- Streak
- Brown
- Luster
- Resinous
- Transparency
- Opaque
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Sedimentary
- Typical price
- $10-50 per specimen
Where rockhounds find tabbyite
1 mapped spotsClassic worldwide localities
- Tabby Canyon, Utah, USA
- Uinta Basin, Utah, USA
Field-hunting tip
Look in sedimentary country, the host setting where tabbyite typically forms. If you start seeing sandstone, shale in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah. Start trip planning there.
Common questions
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Find tabbyite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
