Casale Marble Assortment (TMSS 3/8 Inch 10mm) Closeout


Out of stock


Casale Marble Assortment Mosaic Tiles Tumbled 10mm are sold loose by the pound for making mosaic art, murals, and floor medallions. The NOMINAL dimensions are 10mm (3/8 inch) cubes, but the tumbling process removes material, particularly with softer varieties of stone, and so the width of most stones is probably closer to 5/16 inch than 3/8 inch. Make sure you read our IMPORTANT INSTALLATION TIPS below to avoid grout staining and enhance stone colors.

Important: This is a close-out product! Once it’s gone it’s gone! Please check out our newer Marble Cutting Strips which are thinner (6mm) and therefore give you more square footage per pound.

Marble Mosaic Tiles Tumbled 3/8-Inch

  • tumble-finished natural undyed stone.
  • material varies by batch for color, pattern, size, and sharpness of corners.
  • Each tile is approximately a 5/16 inch cube, with variation by stone type.
  • Recommended for dry locations where water cannot pool.

Material Clarification

Many varieties of marble mosaic tile are not technically marble. Other varieties of stone are used to provide colors not available in marble, but all our marble mosaic is undyed natural stone with an unsealed tumble finish.


Tile thickness is approximately 3/8 inch, which is thicker than our regular glass mosaic tile. If you are pressing tiles into thinset mortar or concrete, then it would be possible to use these with thinner glass tile, but it would be problematic if you are gluing tiles to a flat surface.

Cutting Tile

Our Compound Tile Nipper is the recommended cutting tool for stone and other hard materials such as porcelain. A Marble File is extremely useful for shaping hard materials. It is much easier to file off a tiny amount than it is to try to cut off a tiny amount.


Grout will stain unpolished and unsealed stone because it is porous. The stone has to be sealed with a tile and grout sealer BEFORE you grout it. (Or a type of sealer known as “enhancer” if you want to make the colors darker and richer.) However, you shouldn’t seal any surface where grout or glue needs to stick to the stone. Here is what we recommend for presealing porous materials before grouting:

  • Glue or cement your mosaic tiles into place.
  • Use a rag dampened with sealer or a small artists paint brush to seal only the top faces of the tiles.
  • Take care not to drip sealer down between the tiles or down the sides of the tiles.

Tile and Grout Sealers are available at building material stores. Enhancers are also available there if you want to make the colors of your stone darker and richer. Both products are penetrating sealers instead of coatings, which means they don’t form a layer over the top of the mosaic.

Using Marble Tile for Outdoor Mosaic Art

Most people think that stone is more durable than glass for outdoor mosaic art, but actually the reverse is true for several reasons:


Not all stone is hard, and natural stone only comes in so many colors. To get the range of colors needed to make a mosaic, softer varieties of stone such as honey onyx (actually a calcite) are sometimes all that is available for a particular color. This is especially true when you are discussing affordable types of stone. Sure, emeralds are a rich green, but they are also relatively rare, small and expensive.

Porosity and Freeze Damage

Glass mosaic tile is non-porous, and thus water cannot penetrate into it and then freeze and expand, which causes porous stone to crack and flack away. Keep in mind that the reason we have so many ancient Greek and Roman mosaics left after all the millenia is that the Mediterranean climate is relatively warm and dry. It also helped that many of the ones we now have were buried under volcanic ash for centuries.

Chemically Vulnerable

Remember that not all marble mosaic tile is technically marble, and even if it were, marble isn’t that hard, and it is also susceptible to chemical damage by naturally occurring substances. For example, the products of decaying organic matter such as rotting leaves are acidic. Marble dissolves in acid. (You can actually listen to mable fizz when you pour vinegar on it.) This is how the acid rain from automobile exhaust in European cities has melted ancient statues. Other varieties of stone are also vulnerable to organic acids and other natural substances.

How To Make Marble Mosaics Last

Marble (and the other stone types described as marble) are best used for indoor mosaics where water cannot pool on the surface. However, marble can be used outdoors provided you seal it very well with a tile and grout sealer and check the seal every few years to make sure that water is still beading on the surface instead of soaking in and wetting it. This really isn’t extra work. Even if you used non-porous glass tile, you would still need to seal the mosaic and periodically check the seal because the grout between the tiles is porous and vulnerable to freeze damage.

Outdoor mosaics made from marble should be on vertical surfaces such as walls instead of horizontal surfaces such as the seats of benches or walkways.

How To Make Mosaic Art

For more advice on designing your mosaic project or mounting, cutting, and grouting tile, please see our page of Mosaic Frequently Asked Questions or our Mosaic Information Guide, which lists instructional pages described by topic. We also post new articles about making mosaics at our How to Mosaic Blog.