Basalt: The Puzzling Stone

BASALT: the Puzzling stone

By Mark Ortiz, Stone Restoration Specialist

This months subject is about a puzzling stone on the market and why it is so. As with many new stones on the market, it takes a while until we get a better understanding of their nuances. Coca Cola used to say in it’s marketing ads, “There is nothing better than than the real thing.”  I agree, but to appreciate and promote the real thing about stone, we need to learn as much about it as possible.


Before you read on with my perspective of how Basalt is used, I’ve attached a 2 minute YouTube link to a geological understanding of Basalt in its natural environment. Nick loves natural stone. If I ever retire this may be me one day!

You cannot tell me that wasn’t a pretty cool video of the formation of Basalt. Like all natural stones, it's an amazing work of God's creation that we get to gaze at, touch and use in multiple ways in our own homes and businesses. Let’s see what our geologist professor tells us what about Basalt.



What is Basalt?


Basalt is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt. It is a fine-grained substance with varying shades of color from grey to black. Basalt is an intergalactic rock as well with samples found on Earth’s moon, Mars, Venus and on several asteroids. Most of the ocean’s floor is composed of basalt rock.



Here is my wife Kerri and me at T-Rocks, a cool place in Quartzsite Arizona just past the California Arizona border. We always stop at this place to look at minerals and rocks on our way to see family in Mesa. I’m holding a piece of Basalt.




What are the benefits of Basalt?


Every stone has benefits, whether it’s based on color, design, practicality or durability. In my experience, I have noticed Basalt best used in dry locations such as walls, veneers, floors and fireplaces. It’s a hard stone meaning it doesn’t scratch easily from normal use. Because of its monochromatic charcoal to black color it can be used in multiple applications for both the residential and commercial industry. Being volcanically formed it is also able to withstand tremendous amounts of heat.



What are the concerns?



Since the stone is very porous, it stains easily. When Basalt stains, the stone creates black spots or markings. Imagine if Basalt was on a kitchen floor and after a zinger of a party you wake up to see hundreds of dark spots that do not clean up! This is common for Basalt flooring in high use areas or areas with high oil exposure. Basalt dries out pretty well when exposed to water so showers should not be a problem, right? Wrong.  Soaps, oils and other liquids often used in showers can stain and leave permanent discoloration. Shower walls are usually ok, but benches and floors stain easily.




 What is the Solution?


Perfect Granite Solutions is in the business of finding solutions for stone problems and providing long term maintenance care. The first defence is to avoid applications that will easily produce stains.


Areas not recommended by PGS:

  • Kitchen counters and floors
  • Laundry counters and floors
  • Bathroom counters and showers
  • Restaurants or Salons

I know that seems like a lot of areas but these are the common areas that I see the most problems. These other areas are beneficial, wear well and look amazing.


Areas PGS recommends:

  • Exterior Flooring
  • Interior flooring ( not in bathrooms or kitchens )
  • Walls, wainscot, veneers, exterior wall caps
  • Fireplaces
  • Commercial lobby floors

Does Sealing Help?


Sealing is the best protection against staining on Basalt, but let me assure you, that almost all penetrating / impregnating sealers on the market are ineffective against the porosity of Basalt. We have tested the “best” penetrating sealers with aggressive testing and all failed! That's right, all.  I’m not one who sells sealer therefore I have no bias towards one over the other. Quality penetrating sealers are intended help prevent staining, therefore we encourage sealing, More effective then penetrating sealer are topical sealers. Topical sealers provide a barrier on the stone protecting it from staining. Floors and locations exposed to water and soaps should be sealed with a topical sealer. Testing is important because many of the sealers are too glossy or make it darker. This leads us to Enhancers.



Enhancer Sealers


A proven solution to appreciate basalt is sealing with a stone color enhancer. When the stone discolors from oils or liquids, it turns dark or black. Since the stone is already dark (charcoal / black) after enhancing. the staining is less obvious. This is very effective, but samples should be provided to ensure the customer accepts the dark color. Once you apply an enhancer, it is permanent and cannot be removed.


Why do new installations look blotchy?


New installations often look blotchy, inconsistent, vary in color shades and mark up easily from either installation, construction trades or it just came in that way. Cleaning doesn’t often solve the problem, nor does sealing. If a new installation is too blotchy, we have to lightly refinish the stone to create an even finish. Once the stone is refinished then we go back and look at the options of sealing or enhancing.


Basalt had been pretty challenging for us since it first came on the market, but we have been able to solve the problems and better communicate with the customer. If I was selling or installing stone to clients, I would say something like the following.

“ Basalt (or Lava Rock) can be one of the coolest stones to look at but if you are not aware of its characteristics it can be challenging right from the beginning. Because it is very porous, we recommend avoiding installations where high water, soaps and oils are present, such as kitchens, showers and commercial restaurants. In addition we highly recommend it to be either enhanced or sealed topically. Consulting a professional sealing company will ensure the best possible protection and maintenance is provided.”





It is almost impossible to describe the actual results or how effective the sealer will be for Basalt. Bring us samples of the Basalt you are going to use and I will do some samples for you to test the effects of staining liquids. Our experience with customers after Basalt was installed is usually less than satisfied when it comes to practicality. After education and proper treatments are applied, we usually help them become more accepting of their stone. Consider how we can help you on your next Basalt project.




Pass this useful information to your staff and everyone associated with the stone industry. Let us know if you want to be added to our Monthly Education Newsletters.


Do you have a topic that the industry needs to know about? Email it to me:

Write a comment

Comments: 56
  • #1

    Wendy (Sunday, 17 May 2020 15:13)

    Hi, I am in a quandary. I have a new natural basalt outdoor wall fountain, with a planter wall with basalt capstones. The stone is not sealed. The stone is turning yellow where the fountain water cascades down the front. I presume it is algae, although I always thought algae was green. Can you recommend how I can clean my fountain and eliminate the algae? I have tried a white vinegar solution, but not really helping. I am not sure if you are a question and answer guy, but I could use the advise.
    My email is .....
    Thank you, Wendy

  • #2

    Hewitt Berrien (Tuesday, 06 April 2021 00:44)

    Pair of basalt columns ~30”x ~14” polished on top and one flat side, a water feature, now 3 yrs old and showing stains, blotching, etc. Can a regular guy refinish or be done pro?

  • #3

    Mark Ortiz (Tuesday, 06 April 2021 17:54)

    Hello Hewitt. Clean the polished and honed smooth sides with Barkeepers Friend cleaner and white scrub pads. This will remove all the surface contaminants without removing the polish. If you need some shine, wipe on some carnauba wax. Let me know if you need more assistance. Mark

  • #4

    Eric Gieszl (Wednesday, 19 May 2021 01:39)

    When you refer to Barkeepers Friend are you talking about the powder cleaner that you use on stainless steel or the product that I just discovered they make for stone surfaces?

    Will this remove water spot stains from a bathroom floor with black basalt?

  • #5

    Mark (Wednesday, 19 May 2021 22:06)

    Hello Eric,

    I am referring to Barkeepers powder and I have not heard of Barkeepers for stone. I’ll look into that and see what its all about.

    Water spots on Basalt flooring turns either dark or light. Dark spots are soapy or oily in nature and will most likely be permanent and noticeable until the basalt ages and darkens from normal wear and cleaning. White spots or light spots could mean a soap is removing the sealer or soiling “stripping” away the sealer or soiling. Either way only scrub with a green scrub pad to hopefully blend or remove. Remember, basalt does best when it ages over time. Email me a picture and maybe i can help you more.

    Good question.


  • #6

    Mark (Wednesday, 19 May 2021 22:10)


    I looked into the Barkeepers stone cleaner. It is the same as the rest of other stone cleaners. It’s a neutral ph soap, non rinse. Don’t change your cleaner for your counters if you like the one you are using. It may not be recommended for floors because it has a polish in it. Polish additives usually are slippery.

  • #7

    Melinda (Tuesday, 25 May 2021 13:20)

    We just had a dining room fireplace installed and used Jeffrey Court basalt herringbone mosaic tiles on the surrounding sides. The tiles have not been sealed or enhanced. Is it necessary to do so on wall applications? We love the shade of gray that the tiles have and are hesitant to have them darken. Also, the trim pieces are labeled honed so will the sealant act differently on the trim than on the mosaic?

  • #8

    Mark (Tuesday, 25 May 2021 22:32)

    If you expect anything oily or soapy to come in contact with the stone for cleaning or normal wear and tear then I would seal it. Use either Tenax Pro Seal or Dry Treat Stain Proof only! Make sure you don’t use anything could darken it. Follow the instructions and you should be fine. If you think there is nothing that is wet or oily coming in contact with the stone, then leave it alone. Hope this helps. Mark

  • #9

    Debra (Sunday, 13 June 2021 10:02)

    We have an etched basalt fireplace. During our current remodel it has become stained looks yellowish. We had a T&G ceiling installed & also floated tile floors (a lot of moisture in the house during this process). Not sure what caused it but there is staining & it looks very blotchy allover. What can we do to remove the stain & improve the look? Thanks, Debra

  • #10

    Mark Ortiz (Monday, 14 June 2021 09:02)

    HI Debra,

    Etching is not a common characteristic on Basalt. Etching usually occurs with acidic based liquids pitting “etching” the surface causing the reflection to appear different. For starters just scrub with a cleaner such as diluted simple green and a stiff nylon scrub brush. Do the whole hearth the same. Let dry for about 10 minutes. The next step if the yellow is mineral in nature, you can use a mix of bleach and water. Start with 75% water 25% bleach and let it set for about 30 seconds then scrub with nylon brush, rinse and dry.

  • #11

    Lynda Moses (Tuesday, 24 August 2021 17:54)

    I have a water stain on my Basaltina counter. How can I safely remove the stain?

  • #12

    Lauren (Thursday, 02 September 2021 13:05)

    I'm considering using basalt as a bathroom double vanity top. I do not mind it darkening, in fact I would love the stone to be generally darker, more like how soapstone looks after waxing/oiling. If I use a color enhancing sealant, would it face further staining or maintenance, or will the stone stay pretty much uniformly dark? We have soapstone kitchen countertops and a white marble island, so I'm fine with imperfections ;)

  • #13

    Mark Ortiz (Thursday, 02 September 2021 13:59)


    If you are familiar with basalt and you really like the color and grain, then I would say yes! Definitely enhancer or darken if for the reasons you are aware of.
    Also place coasters or napkins under the soap dispensers to prevent rings or spots. My customers that enhance the tops and follow simple instructions have excellent success with basalt. If you have a messy roommate....go with soapstone. Haha.

  • #14

    Lauren (Monday, 06 September 2021 15:28)

    Thank you for this great information! For clarification, we may still get rings and spots after enhancing and using a topical sealer? Blemishes are totally ok and add character, but I also don't want a high maintenance surface. Again, many thanks!

  • #15

    George S. (Monday, 01 November 2021 22:04)

    What would you recommend to darken Basalt flooring that is blotchy and has whitish stains due to hard water. Nothing seems to clean the white stains, so I am thinking the darker the better. Can a dark tint be added to the color enhancers you recommend?

  • #16

    Mark Ortiz (Wednesday, 03 November 2021 17:12)

    George S.

    If you are sure it is hard water deposits, you can try a mild acid cleaner. Start with vinegar first. If it removes it and you like it then leave it as it is. You can bump up the acid with a diluted CLR (start with 1 part acid to 10 parts water and work your way up.)

    The only 'tint' I would try is Uni-black mixed in with Hydrex. Both are made by TENAX. I'm sure there are other types but this is the one I have tested many times and the stain is compatible. Start with a 12 oz. plastic spray bottle filled half way. Add a little Uniblack to it. A teaspoon maybe. Then mix and spray on. Wipe in with a microfiber rag. This is a very scary procedure because it darkens right away and you may need to do it several times or add a little more Uniblack. If you are not confident with your staining abilities then maybe you shouldn't move forward. If you don't mind it being really dark, then keep going, you can't go wrong. You can email me at info@perfectgranitesolutions with photos and more tips.

  • #17

    Erin (Monday, 13 December 2021 23:00)

    We just set our large slab of basalt down above our new fireplace health. I’m embarrassed to say I tripped and spilled a to. Of melted butter all o er before we could seal it…uuuuugh my husband may kill me. I was told by two tile stores to use a poultice, so I began to, but noticed an awful stain it’s maid and seem to have etched it some(if that’s the right definition??). I was wondering if there is any hope?? Not sure what to do now…try more, or maybe I need to use a dark enhancer??? Please help!

  • #18

    Courtney Williams (Sunday, 06 February 2022 09:50)

    We just installed basalt pavers in our driveway. It looks fantastic! It was sealed with a water based sealer, glossy that darkened and shined it really well. Unfortunately, I am seeing water spots from the sprinklers and we also encountered a white coating in one section near where the street was being pressure cleaned. Do you have any suggestions to remove the white coating and water spots?

  • #19

    Mark Ortiz (Sunday, 06 February 2022 21:23)

    HI Courtney,
    I wish you would have read my newsletter before sealing it. What you had done was an application of a topical sealer. I know because you said it was glossy. Only a topical sealer can make it appear glossy. The spots on from the sprinklers can be cleaned with a green scrub pad and water. Sometimes it will require a diluted hydrochloric acid to dissolve the hard water deposits. After you clean off the spots, you may or may not need to wipe the same sealer on that area. Adjust your sprinklers away from the stone.

    The white coating near the street is probably due to moisture absorbing from underneath the stone and it is lifting the bond from the sealer off the basalt. It is a air pocket producing the whitish area, similar to a blister on your finger. This usually requires that section to be stripped with a wax stripper back to the stone and then re-apply the sealer.

    Lastly, that sealer will probably look good for about 2-3 years and then need to be completely stripped off. Cross your fingers. Once you strip it off completely then instead apply a stone color enhancer sealer instead. For now…enjoy the beauty of Basalt.

    Thanks for the comment.

  • #20

    Courtney Williams (Monday, 07 February 2022 04:26)

    Thank you Mark! I really appreciate your expertise and feedback.

  • #21

    mattie (Friday, 11 February 2022 11:27)

    Hi! I just purchased this basalt mosaic tile ( to put in a sunroom and after starting to lay it out, it appears that each piece varies in darkness so you can tell where each piece starts and the next one ends. Do you have any advice on if there's a way to use enhancer/sealer/something else to try and unify the color? Or are my only realistic options to either go with another tile or deal with the inconsistencies? Thank you!

  • #22

    Mark Ortiz (Friday, 11 February 2022 12:09)

    Hi Maddie! I would try sanding the two pieces that are opposite shades. Use a 120 grit sandpaper. Wet or dry. Then clean off. Once dry, seal with an enhancer. If it looks consistent then that’s the solution. The size of the pieces may need each one hand sanded verses using a floor machine. It seems like a lot of work but you will not have to do it again in the future.

    I usually machine hone installed basalt because of inconsistencies. Then enhance.

    Let me know. Mark

  • #23

    mattie (Thursday, 24 February 2022 08:15)

    Thanks Mark! This was very helpful. We did a test with the 120 grit sandpaper and it did seem to really help. That said, we decided the first safest thing to do was to cut the larger mesh into 6 individual hexagon pieces, randomize them and install to minimize large swaths of color variation and make any variations smaller/more localized. This turned out to be enough. I think sanding could have helped even it out even more but we were afraid of being able to see sanding marks and chicken'd out :-). We then used this sealer ( and applied it twice. There was a bit of panic in that process as it left streaks, showing the paths we took when applying it. Fortunately, though, after grouting and cleaning, those have gone away and it looks great. We are not going to touch it again (ha!). Happy to send along a photo if you are interested. ~mattie ruth

  • #24

    Mark Ortiz (Thursday, 24 February 2022 16:24)

    Mattie. I'm very glad to hear your floor looks great! I like the process of cutting the mesh and re-laying! That's old school skill there...good job. The streaks are from the sealer being topical. The sealer works good but you may still see stains if the liquid is left on too long. If you apply more sealer, use a micro fiber rag and apply thin applications in circles. That should help prevent streaks. I WOULD LOVE PICTURES! I WOULD HOPE TO POST IT ON THIS NEWSLETTER FOR OTHERS TO SEE.

  • #25

    Sheryl (Friday, 11 March 2022 15:53)

    Three years ago we installed basalt along our spa wall along our pool. We know have significant calcium build up in a few places where the water was dripping/ running.

    Can you suggest how to remove this ?

    Thank you

  • #26

    Mark Hodges (Wednesday, 27 April 2022 02:13)

    I applied colour intensifier on bassalt on a clients patio outdoors.

    The sealant has left awful dark oily patches all over it .
    Has anyone tried anything to remove this on paving outdoors ?

    any help would be so appreciated

    Many thanks

  • #27

    Mark Ortiz (Thursday, 28 April 2022 10:02)

    Mark H. Without seeing pictures of the issue of oily spots, I'm going to assume you applied the intensifier per instructions and that it is not the intensifier causing it.

    My guess is this: The Basalt has inherent dark mineral or "patches" of minerals that are darkening more than the surrounding stone. Once you applied the intensifier, it highlighted those minerals.

    I would try applying a paint / epoxy stripper on the stone, let set for about 30 minutes and then clean it up with simple green and water a few times. Dry and check. If that worked, then it will be a long day, but eventually it will come off.


  • #28

    Tom Hansen (Wednesday, 18 May 2022 01:24)

    Hi Mark,

    We have non sealt Basalt on our kitchen. My wife by mistake used a Toilet Cleaner that contains acid. It now has white/grey spots from the acid. Will it help to use a darkened to hide the spots or do you have a another suggestion on what to do?


  • #29

    Mark Ortiz (Thursday, 19 May 2022 19:27)

    The acid will whiten the stone but it should not have etched it. Etching is when there is a significant dullness reflected at an angle. If it dulled or pitted, then sanding with a 120 grit and possibly 220 grit sand paper should remove the etching. Over time the sanded area will blend in.

    Yes, add an enhancer sealer on that area, and you may need to do the whole surface for added improvement and overall consistency. Wipe off excess sealer enhancer right away so it doesn't streak.

  • #30

    Vicki (Thursday, 04 August 2022 06:50)

    Hi, We have a basalt tile backsplash above our range and extending to the 25 foot high ceilings. It has some grease spots showing up on it that obviously are not washing off. It has been sealed but I'm not sure what sealer was used. Is there any way to remove these grease spots? Thank you!

  • #31

    Mark (Thursday, 04 August 2022 08:07)

    Hi Vicki. Send me a foto and I’d be happy to help.

  • #32

    Mike S (Saturday, 15 October 2022 08:38)

    Hi Mark, great article. I have three basalt columns in a water feature. Yr 1 they used chlorine to keep the algae down. Ruined three pumps. Yr 2-3 used fountec algae preventer. First year all ok, 2nd yr green algae scrubbed off with plastic brush, now there’s a whitish algae comes off easy enough. will drain the pond after a through cleaning of the columns and refill the water any other suggestions? Some of the basalt chips/falls off so hesitant to use power washer on them. Thanks mike

  • #33

    Mary Wenzel (Friday, 10 February 2023 19:42)

    I have a property with over 1500 sq ft of discolored Basalt tiles from indoors to out. It has white haze all over it. What cleaning solutions should 1 be using? We own a carpet and stone cleaning business. We have just never run across this problem.

    Mahalo in advance.

  • #34

    Mark Ortiz (Friday, 10 February 2023 20:49)

    Hi Mary…the white haze is either a previous topical sealer separating its bond to the stone, or mineral deposits settling on the surface.

    If it’s a sealer causing it, then you will need to apply a stripper and follow instructions. If it’s minerals, you can use hydrochloric acid. Brushing with floor machines is key. Afterwords you can steam clean.

    Do test spots with both stripper and acid and see which one works.

    Hope it works!

  • #35

    Kelly Grudzien (Wednesday, 12 April 2023 14:56)

    This is such a great forum. We were amazed by the beauty of the black bassalt recommended to us for our outdoor BBQ countertop and unfortunately didn't really do the research about the color changes that would occur. It was so beautiful for about a month or 2 and now there are large white spots that make it look terrible. The person who installed it came back to put on another coat of sealer (not idea what he used) and it seems to just enhance the white marks. Someone said to try shoe polish, but that seems weird as I wouldn't want the polish to come off on anything. I am not sure who I would even contact to come help us as the installer went M.I.A (as he probably knew we would have issues with this stone). Any ideas? So happy to send pictures if given an address.

  • #36

    Mark Ortiz (Wednesday, 12 April 2023 20:38)

    Hi Kelly. Thanks for the compliment. As you have read by others, the most noted concern are stains or dark marks....not white marks. There are factors I would need to know before giving you advise. My questions would be, is the bbq covered from the elements? What is the weather like where you are at? Knowing the sealer truly helps to solve this problem. White marks are often from either sealers reacting with setting water, or minerals in the stone coming to the surface, or something caustic removing the stone darkener. Usually, we strip and clean the stone with a course pad until even and then apply a stone stain and then a penetrating sealer.

    PLEASE SEND ME PICTURES TO ...... and I'll be happy to do what I can to help.

  • #37

    Max Shikhman (Monday, 15 May 2023 19:37)

    Hi I know you strongly discourage basalt stone installation in places where high water and soap usage like shower floor but is there any sealer that could possibly protect it? I just cant find anything I like that would come close to this:

  • #38

    MarkOrtiz (Tuesday, 16 May 2023 09:57)

    Hello Max. The walls will be fine, but the floor will get discolored for sure. There are two brands that will keep the stone the charcoal black color and another that will darken it. All will have good protection, yet you will need to keep the shower door open after each use and let the stone dry out naturally.
    Keeping it the natural color: Use either Tenax Pro Seal or Dry Treat Stain Proof for maximum protection against absorption. It will require 3 applications day one and 2 more day 2. Do not use for 72 hours.

    To darken and seal: Use Customs Enrich and Seal. Two applications day one (wipe off excess!) and one application day 2. Do not use for 72 hours. Warning: Once it seals, it will not return to the lighter charcoal color.

  • #39

    Max Shikhman (Wednesday, 17 May 2023 20:25)

    Thank you Mark super helpful! I just have last few followup questions:

    1. I assume your recommendation on sealing is done before grouting, right?
    2. Do I have to do both seal and darken or I can just pick either option depending on the preference?
    3. Will the seal make the stones slippery or shiny?

    Thanx again!!

  • #40

    Mark Ortiz (Wednesday, 17 May 2023 21:38)

    Seal before grouting and one more application after grouting.
    You have to pick either one. Enhancer will not darken after natural seal.
    It will not be slippery, but at first the stone will repel water a lot. I recommend clean the floor after the 72 hours with a green 3M scrub pad and dish soap which will remove the beading and ensure it remains non slip.
    *** Always be carful with soapy shower floor.

  • #41

    Aaron (Tuesday, 01 August 2023 16:56)

    Had a tile guy install a basalt shower floor. Looked great until it was sealed. Tiles are all blotchy with dark spots now. Is this fixable?

  • #42

    Mark Ortiz (Saturday, 05 August 2023 07:43)

    Hello Aaron. Not sure what sealer was used, so the source of the blotches is not certain. If he used a natural penetrating sealer then it could have been moisture still in the stone. If it was an enhancer then it could be the natural inherent dark minerals now becoming more pronounced. Over time that shower floor will become blotchy from soaps, oils, and water. If the blotching is from the natural minerals then more enhancement is my suggestion. I would need more information to diagnose it properly.

  • #43

    Daniel Lewis (Saturday, 12 August 2023 11:37)

    Hello Mark,

    I just found this page and is full of great advise! How do I get added to your newsletter?

    Thanx, Daniel

  • #44

    Tim (Sunday, 13 August 2023 05:35)

    Hi Arron,
    I had a installer lay basalt shower floor. He must have not know it needed to be sealed prior. The floor looks terrible now. I have grout that hasn’t been cleaned good enough on some the tiles and it looks dull. The installer used a grout releaser prior to grouting as well. Should I sand it as you described on some of your other helpful tips and then of course seal it? Or can you recommend a better way to clean it?
    Thanks.. Tim

  • #45

    Luiz (Sunday, 17 September 2023)

    Hello Mark,

    Great article! It really opens my eyes to using basalt in the future, but too late for my problem now! We have basalt floors on a rental place and the latest guest left some oily dark stains that I have no idea what it is. Looks like maybe sunscreen and red wine stains. I’m tempted with the idea with the enhanced sealer to darken the whole thing , but would really like to try and keep the original look. What would you suggest I use to clean it? Thanks much.

  • #46

    Mark Ortiz (Tuesday, 19 September 2023 18:24)

    Hello Luiz.

    Taking oil out of basalt is not easy. Purchase a poultice online, like
    And follow the instructions. After you feel confident in the results, you seal with a water based penetrating sealer. After the penetrating sealer apply a topical sealer at Home Depot called Customs matte finish sealer. This is the easiest way to get the best protection and keeping it lighter gray. Good luck my friend.

  • #47

    Deen (Thursday, 12 October 2023 17:16)

    Hey mark I just recently made my house and seller didn’t tell me that colour would change over time ! I have bought it in honed finish in dark grey finish and it’s been few days it’s already coming to its original colour which is light grey ! How do I stop it becz my whole theme is grey and it would destroy my exterior ! Secondly he wrote something on it with marker how to remove that , thirdly i wanna fill it grout how should I do it because I tried it with just a few parts and it’s catching grout colour and it’s not going away !!! Please help me out before it’s too late for me

  • #48

    Mark Ortiz (Friday, 13 October 2023 00:54)

    Hi Deen. I don't completely understand your concerns. I have a few questions before we can find you a solution. Try emailing me at and I'll help you further. Send pictures so I know exactly what you are requesting.

    Try removing the marker with paint stripper. Rince it with water right after.

  • #49

    Joan Lynch (Sunday, 29 October 2023 21:02)

    Greetings Mark,
    What an informative piece. Your answers to questions posed in the comment section are very helpful. We installed a basalt tile lanai at our home in Maui. Unbeknownst to us, the homes are frequented by hundreds of cattle egrets, who hang out on the lanai and drop their poop when we are away. As you can imagine, once baked on it becomes very difficult to remove from basalt tile. We use a power washer.
    Would putting a topical sealant make the problem easier to solve, i.e. the mess easier to remove? Would we be able to hose it off vs. use a power washer? I fear the power washer would destroy the sealant. This problem has become so bad I am consumed by it. If you saw the pictures ( more than willing to send) you would understand that I am not exaggerating!
    Best regards,

  • #50

    Mark Ortiz (Monday, 30 October 2023 20:24)

    Hi Joan...I had to look up Cattle Egrets because I thought it was another name for cow patties, but in Hawaii? So you have those irritating birds that poop all over your basalt patio? When those warm droppings land on the stone, it penetrates the surface and dries , making it difficult to remove. Power washing is good, but if its too much pressure, it may leave lines, if there's not enough pressure, it doesn't work. Try setting about 5 fake snakes and see it that scares them away. But seriously....
    I think a topical sealer will be helpful in your case. I like a product called Desert. But you will need my help picking the right one. Send me a few pics and we can work on it. Send pics and contact info to Thanks for your questions.

  • #51

    Joan (Friday, 03 November 2023 15:18)

    Oh thank you for responding! I’m sorry but silly me only checked my email. I am sending pictures to your email. Get ready for a horror show lol!

  • #52

    Hannah Hamby (Wednesday, 15 November 2023 18:26)

    Hello, I had a niche with a black basalt tile for where the shampoos and soaps go. It is now cloudy and turning white. How do I fix it? I can email you a picture.

  • #53

    Ryan Topdjian (Monday, 11 December 2023 01:25)

    Wow what a great read. I have been working with basalt specifically for 2 years now. Making water features and polishing large surface areas. I loved the geology video you recommended as well so I can sound smart at work.

    I haven’t had any luck with sealers that resist water stains. We do a lot of outdoor benches and it rains a lot here in WA.

    Is there any “natural” sealers that would resist water but would work for high traffic like sitting and lot of sitting water. I’ve heard of bees wax to boiled linseed oil. I personally use Tenax Tiger Ager.

    Any recommendations on how to get the absolute best finish? I polish to 10,000 grit and seal it, do my best to level and plane it before I polish but I work with 2’ x 9’ slabs.

    Again, loved this article I gave a real passion for my work. Thank you in advance!

  • #54

    Mark Ortiz (Wednesday, 13 December 2023 02:47)

    Ryan, we would need to talk about sealers and refinishing over the phone. Call me when you have a chance.

  • #55

    Shane M. (Saturday, 30 December 2023 16:05)

    Hi Mark!
    Your insight is super helpful. So thank you! My wife and i have a dark gray basalt tile backsplash in our kitchen that's about 2 years old. And over time, maybe from the acid in lemon or lime juice, the tile seems to be discoloring to like an orangish and even white splotches in one really big area. The area is usually where we are entertaining guests. And we think maybe it's from the juice squeezing too close to the wall. I can't find any way to remove the stains. Any suggestions on what i can use? The tile was sealed right after installation. Thanks in advance!

  • #56

    Bryan (Sunday, 12 May 2024 13:44)

    Hi Mark,
    I installed basalt tile in my foyer. I wasn't thinking and grouped before sealing. I have tried the Stone Tech grout haze remover, but there it looks as though the haze is impregnated into the stone. Any recommendations on how to remove it? Thanks!