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Igneous

Basalt — a natural stone guide for buyers, designers, and contractors.

Basalt is a igneous stone sourced primarily from Pacific Northwest USA, Iceland & China. With a Mohs hardness of 6 and water absorption of 0.2%, it is commonly used for Outdoor paving, pool surround, cladding.

6Mohs hardness
0.2%Water absorption
OutstandingFreeze-thaw
$8–20 / sq ftTypical cost range

By the numbers

Mohs hardness 6
Water absorption 0.2%
Freeze-thaw Outstanding
Density 2.90 g/cm³
Applications Outdoor paving, pool surround, cladding
Cost range $8–20 / sq ft

Surface options

Honed

Matte, flat surface. Most common for interior flooring and walls.

Polished

High gloss finish. Maximizes color and pattern depth.

Brushed/Flamed

Textured surface for exterior use and slip resistance.

Pros & cons

Advantages

  • Natural, one-of-a-kind appearance
  • Origin: Pacific Northwest USA, Iceland & China
  • Freeze-thaw performance: Outstanding
  • Cost range: $8–20 / sq ft
  • Suitable for: Outdoor paving, pool surround, cladding

Considerations

  • Requires sealing and regular maintenance
  • Heavier and more expensive to install than synthetic alternatives
  • Color/pattern variation between batches

Basalt — common questions

Basalt is commonly used for Outdoor paving, pool surround, cladding. Its Mohs hardness of 6 and Outstanding freeze-thaw rating determine where it performs best.
Basalt has a Mohs hardness of 6. For reference, granite is Mohs 6–7, marble is Mohs 3–4. Higher hardness means better scratch and wear resistance.
Basalt has a water absorption of 0.2%. Stones with higher absorption benefit most from a penetrating sealer applied annually. Always test with the water-drop test: if water absorbs in under 4 minutes, reseal.
Basalt typically costs $8–20 / sq ft per square foot for the material. Installation adds $8–$20/sq ft depending on complexity and region. Request current pricing from SmartStones verified suppliers.
Basalt is rated "Outstanding" for freeze-thaw performance. Its water absorption is 0.2%. Lower water absorption = better freeze-thaw resistance. For northern climates, verify the stone meets your project's freeze-thaw requirements.

How to Care for Basalt

Essential maintenance steps to keep Basalt surfaces looking their best for decades.

1

Daily cleaning

Wipe with a damp microfiber cloth. Use a pH-neutral stone soap for weekly cleaning. Avoid vinegar, bleach, or multi-surface cleaners.

2

Blot spills immediately

Blot (do not wipe) any spills to prevent staining or etching. Rinse with water and dry.

3

Annual sealing

Apply a penetrating impregnator sealer to dry, clean Basalt. Allow 10–15 minutes of dwell time, wipe excess, and cure for 24 hours. Re-seal when the water-drop test fails.

4

Professional restoration

If the surface develops deep scratches, chips, or loses its finish, contact a stone restoration professional. Most damage can be corrected by re-honing or re-polishing.

How Basalt compares

Basalt price guide

Typical material cost
$8–20 / sq ft / sq ft

The full Basalt price guide covers material vs. installed costs, regional pricing across all 6 US regions and Canada, format-specific breakdowns, and the top cost drivers for your project.

Full Basalt price guide →

Find Basalt suppliers near you

Browse verified Basalt suppliers across the US and Canada — current pricing, in-stock inventory, and fast response.