Bluestone is a commercial term for a variety of hard, dense, fine-grained, feldspathic sandstone that splits easily into thin slabs. It is highly valued in construction and landscaping for its durability and characteristic blue-gray coloration. It is primarily found in sedimentary layers, most famously throughout the Appalachian Plateau.
Is this bluestone?
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 bluestone with a known reference. Bluestone sits at Mohs 3-7, softer than the next harder reference, harder than the previous one.
- 2Read the textureLook at a fresh break with a hand lens. Grain size: Sand-sized grains.
- 3Read the lusterHold the specimen under a strong light. Luster: dull.
- 4Match the color rangeCompare against the expected color range: blue, gray, bluish-gray.
Often confused with
Bluestone vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside bluestone
Minerals reported to co-occur with bluestone. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 3-7
- Density
- 2.5-2.8 g/cm³
- Colors
- Luster
- Dull
- Transparency
- Opaque
- Rarity
- Common
- Uses
- Construction, Architectural, Decorative
- Host rock
- sedimentary basin
- Grain size
- Sand-sized grains
Where rockhounds find bluestone
1 mapped spotsClassic worldwide localities
- Pennsylvania
- New York
- United Kingdom
Field-hunting tip
Where it forms: sedimentary basin. If you start seeing quartz, feldspar, clay minerals in float, you are in the right ground. In the U.S., the densest reported localities are in Nevada. Start trip planning there.
More bluestone photos
Common questions
How do you identify bluestone?+
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Can I find bluestone in the United States?+
What rocks look like bluestone?+
What minerals are found with bluestone?+
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Find bluestone on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
