Cleaning & Sealing Bluestone / Basalt

Basalt is a common extrusive igneous (volcanic) rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Basalt is defined by its mineral content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic (iron-rich) minerals into rust. Sealing bluestone is recommended for stain resistance and maintenance purposes.

Type of Finishes


Polished Bluestone/ Basalt

A glossy, highly reflective surface

  • Surface is very smooth and not very porous
  • Polished crystals bring out brilliant colors and grains (400 to 3500 grit to polish stone)
  • Shine comes from the natural reflection of the stone’s crystals
  • Polish can wear away due to heavy foot traffic and improper maintenance

Tumbled Bluestone/ Basalt

A slightly rough texture that is achieved by tumbling small pieces of marble, limestone or granite to achieve an old-world/worn appearance

Honed Bluestone/ Basalt

A flat matte to low sheen gloss

  • Surface is very smooth, but very porous
  • Many more and wider gaps in surface than polished stone
  • Medium density
  • Commonly used in low traffic areas or for aesthetics
  • Colors are not as vibrant as a polished stone

Sand Blasted Bluestone/basalt

Pressurized flow of sand and water that results in a matte finish

Bush-hammered Bluestone/basalt

Pounding action of hammer develops textured surface. Reduces stone’s color tones

Pre Sealing Bluestone / Basalt

Sealing BluestoneSealing bluestone is highly recommended prior to installation. Many bluestone/basalt contain soluble salts and can often become permanently discoloured from the installation process. It is always best to consult with your stone supplier to verify whether your bluestone requires this treatment. For best results, sealing bluestone on all six sides using Aqua Mix® ProBlock a minimum of 24 hours prior to installation.

Aqua Mix® ProBlock is a water based penetrating sealer designed to resist staining caused by water soluble minerals (including picture framing effect) which are normally absorbed through the back of the stone during installation. It also helps resist efflorescence migration.

If applying an Enhancing Sealer as the final surface seal, DO NOT apply any ProBlock to the top surface as it will stop the penetration of enhancing sealers. Please contact Aqua Mix® prior to installation if an enhancer is specified for use.

Pre-Grout Sealing Bluestone / Basalt

If the stone does not require to be pre-sealed, it is generally recommended to apply a coat of sealer on the surface prior to grouting. This is to act as a grout release and assist in the grout clean-up process.

If the surface is textured (sandblasted, bush-hammered, tumbled) applying a coat of Aqua Mix® Grout Release would work best.

If the surface is smooth (polished, honed) than applying a coat of the final sealer you select is recommended.

Grout Haze Removal

It is important that all of the grout haze is removed between 3-10 days. A minimum of 3 days for the grout to cure and harden, and no longer than 10 days or it may need to be mechanically removed.

Grout haze can be removed using Aqua Mix® Cement Grout Haze Remover. It should be noted that many basalts can react with acidic cleaners. It is always recommended that you test Aqua Mix® Cement Grout Haze Remover on a spare piece first. If Aqua Mix® Grout Release was used, the grout and Grout Release can be removed using Aqua Mix® Heavy-Duty Tile & Grout Cleaner. If epoxy grout has been used you can remove using Aqua Mix® Sealer & Coating Remover.

Sealing Bluestone / Basalt

Sealing BluestoneSmooth surfaces (polished, honed) should only be sealed using either a Natural Look Sealer or an Enhancing Sealer. The best sealer for bluestone/basalt is Aqua Mix® Sealer’s Choice® Gold – Rapid Cure however, we have a range of sealers to suit your requirements:

Sealing Bluestone / Basalt with a Natural Look Penetrating Sealer:

Sealing Bluestone / Basalt with an Enhanced Look Penetrating Sealer:

Note: Sealing bluestone with a penetrating sealer will not alter the slip resistance. For more information regarding slip resistance, click here

If the surface is an internal textured floor you also may use a Topical / Coating Sealer. However, we do not recommend Topical / Coating Sealer to be used in wet areas.

Maintaining Bluestone / Basalt Surfaces

Countertops and Walls

Sealing BluestoneCountertops/Bench-tops, vanities, and walls should be regularly cleaned using any of Aqua Mix® Routine Cleaners.

Regular use of Aqua Mix® Aqua Shield™ Cleaner & Resealer will ensure that your bluestone/basalt always maintains maximum stain resistance.

Aqua Mix® Brilliance is an excellent cleaner/polisher that adds luster to your polished bluestone/basalt, regular use helps protect factory polish.


Floors should be regularly cleaned using Aqua Mix® Concentrated Stone & Tile Cleaner. If the surface is allowed to build up, then scrub the surface using Aqua Mix® Stone Deep CleanAqua Mix® Heavy-Duty Tile & Grout Cleaner or Aqua Mix® NanoScrub® and an Aqua MIx® AquaScrub.

Stain Removal

Sealing BluestoneIf you have a stain that you wish to remove, Aqua Mix® Poultice Stain Remover should be used. This product is a blend of absorbent clays that can be mixed with water or an appropriate chemical to extract the stain from within the stone.

Stain Removal Guide

Require Technical Assistance?

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