How to Make Glass Mosaics on Rocks

There’s always way to switch things up when creating! I love budget friendly design options so using stones is perfect. Here’s my tutorial of how to make Glass Mosaics on Rocks… ’cause I love rocks.

Outdoor Mosaic Options:

The charm of mosaics lends itself nicely to be used outdoors. This method does not use a grinder but only a glass cutter and some tile nippers therefore the pieces are somewhat rustic in style. That works well with using natural elements to work on.

Why Use Rocks?

Well, one reason is that I LOVE rocks! Even though I have not made them I really appreciate the textures and nuance details that they bring to a design. It’s funny how people know me and when they want to give away their rocks or stones ask if I want them. This is flagstone that used to cover a porch. I have read that it’s not advisable to take rocks from nature. Many garden centres do sell various types of stone as well.

The shape and even the extra ‘bump’ gave me some ideas…

Using scrap glass:

As you know from this I have a fair bit of scrap glass. When I am filling certain shapes I look through to see if a piece already fits the shape I need; it is somewhat like jigsaw puzzling. I may be making quite a bit with this glass!

Start your Mosaic design:

One challenge of working on this rock substrate is how to get the design onto the rock surface. As an illustrator (for more than 20 years) I have come across this issue so many times on all kinds of media. Sure, you can draw directly on the surface (with a pencil) or use a projection method. There is an app that allow you to use your phone (or ipad) to see the image while drawing it onto the surface of the rock or other.

There is also the option to use some sort of transfer paper (like a carbon paper) but I find those troublesome since the stone has texture. If you have a drawing (tracing) on paper you can also cut it out to outline the shape. A grid drawing system also works but might seem tedious for such a simple design….

The Adhesive for Rock:

Since this is natural stone it has some great textural ability to adhere to. I am using Versabond Professional Thinset Mortar as the ‘glue’. (follow manufacturer’s instructions) I mix it it to a about a peanut butter consistency and let it sit for a few minutes, mix again and then put it into small plastic bags. Any bags can work (up-cycle), just make sure they are sealed or tied well.

Putting the grout/mortar in a bag gives you more working time as the polymer is less exposed to air. This method also keeps it very controllable and clean. Small areas of this adhesive can be applied accurately when the corner of bag is snipped.

What tools do I need?

One reason I like this mosaic art method is that I am not using a lot of tools & easy setup. Using the odd shapes of the scraps lets me see if any just fit or a bit of nipping with the glass nippers to adjust the shape. There’s no reason some other small rocks could not be added as well (oh, gee some new ideas just popped in my head).

Working bit-by-bit across the surface with a small amount of grout was pretty easy. Use a permanent marker to draw the shape needed to cut. Later on this can be rubbed off with fine steel wool. Here’s a tip: whenever I add a material into a dry porous surface I like to dampen it so that the moisture is not instantly ‘sucked’ out of the addition. This is quite important when working with concrete so I feel similar benefit here.

Adding Piece by Piece:

The Versabond has Polymer added as well so do not add extra water. If any areas need some smoothing a small brush works nicely.

Compared to true stained-glass mosaics this may seem quite primitive, but since it is a natural stone it seems quite an appropriate addition. If any grout gets away from you a damp sponge will clean it off. The grey colour of the Versabond actually perfectly matched the stone. A spatula can also apply the thinset to make sure edges have good coverage. The glass should be imbedded at least 1/3 of it’s depth.

I hesitate to use any type of accelerant as there is some Portland cement component in the mix, and they cure stronger when they have proper reaction to the moisture. That is why this mix has such a hard finish. Any sharp edges can be sanded of using the emery cloth.

How to Make Glass Mosaics on Rocks

Make some unique art on natural stones! This tutorial explains how to make Glass Mosaics on Rocks. This uses simple tools & images.


  • Glass Nippers
  • Sponge
  • Small brush
  • Spatula or Palette knife
  • Glass cutter
  • Mixing Container
  • Mixing tool
  • Rubber Gloves
  • Dust Mask
  • Pencil
  • Permanent Marker
  • Emery cloth


  • Versabond Polymer Modified Thinset
  • Water
  • Glass Pieces
  • Large Rock or Stone


  • Gather Supplies including safety equipment
  • Decide on image and transfer or draw onto Rock surface
  • Choose glass colours and pieces for the design.
  • Mix small amount of Versabond Thinset according to manufacturers instruction.
  • Fill into plastic bag and seal well
  • Snip small corner of bag to allow detail application of grout.
  • Work section by section applying thinset & imbedding the glass shapes that are snipped or cut to shape. (use Marker to draw shape on glass)
  • Once done and cured add additional thinset to areas that need filling or edging. Clean any marker off with steel wool. If some edges are too sharp use emery cloth to round off.

He will be a fun addition to the garden decor. Simple images (like bug, dragonfly, fairy garden) work easily. I will not be flat on the ground as that sometimes allows too much moisture to collect. All my concrete tends to be unsealed so I have kept this fellow without sealer too. Sealer will often change the colour and when it wears out or flakes it is an eyesore.

What do you think? Any ideas for your own? Hint; I’ve got some more methods coming soon… But there is much that can be used to create your own version…

Ribbit, ribbet… mosaic rocks…

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  1. Hi Barb I’m almost 70 years old and trying to think of things that I can do. My husband’s got cancer. He has 1 to 3 years left. I got a find something to do before I go crazy I love your artwork. I love how you made the little frog on the rock. I think I might try that I don’t know where you get all that glass and all the different colors I’ve never really tried anything before, but I thought you could tell me where to get the class so I can try. Thank you for your time and your beautiful artwork. Sincerely. Fran Chambers.

    1. Hi there! I am so sorry about your husband. Art is good therapy! When I took a class for stained glass I saw a lot be recycled so I asked for it. I also saw that local artisans can sell it. I will have a post up soon where I use broken plates instead of glass. That is another option. Small mosaic square can be bought at dollar stores and also on amazon… lots of options. Best of luck.

    1. Oh thanks… I have found that once I allowed myself to explore any idea that would pop into to my mind I am much more creative. Much too often I saw my students in college shut down ideas before they even gave them a chance. ‘Let’ your self be creative! It feeds the soul!

      1. Oh my goodness! This is adorable! I’m trying to figure out how you cut such tiny circles for the toes?! That would be extremely difficult with a glass cutter.

  2. Sooo cute ! You have so many talents for 1 person !!!
    My sister belong to an artistic / diverse retirement community in AZ – she and her hubby spent the winter there. (they are from a Chicago suburb)
    She helps direct the glass arts community.
    I’ve visited, but did not get the time to help make glass art stepping stones.
    Your frog is wonderful. 🙂 Thanks for sharing .

    1. I bet you can. Do read the specs to see how much working time you have as well. There’s good and bad about fast setting times. Reading the specs ia always important for where you will putting the mosaic.

    1. The stone is a piece of flagstone (often available at a garden centre or nature) and the glass was some scrap from a glass artist. Look for stained glass supplies or local artists/classes. Have fun!!

  3. I can’t tell if you used grout after you finished setting the pieces, or was the thin set all you used to fill in between your glass pieces?

    1. Yes, I used the thinset as it is rated for indoor and outdoor use. It is a mortar as well and loved the colour match to the stone. It bonds well since it is also polymer fortified. I’ve got the mosaics outside through the winter to see how they faire… So far; so good!

  4. Hello Brab,
    My name is Sheridan I have spent little time doing SG from a class forever ago! But I have it itch to do some things now. Plus I’m a huge rock hound lol! Thank you for your info I never thought of the two great thing together . I’m going to give it a shot…….thank you my Dear! From my years of floral and Christmas work.
    Thank you again for this idea!!!
    Take care