While both porcelain and ceramic tiles are made from a mixture of clay and other materials which are pressed into a dense mass then kiln-fired at over 1000 °C, it can sometimes be difficult to distinguish between the two.
Although both porcelain and ceramic tiles are called “ceramic tile”, porcelain is by definition harder, denser and absorbs less water, which is why it is less prone to cracking when exposed to cold.
But how exactly do you tell whether a tile is ceramic or porcelain?
1. Check the packaging. Look for the word “porcelain”, as well as a water absorption rate of <0,5% or a Mohs hardness rating of seven or above. Ceramic tiles generally only have a water absorption rate of <3% at best. If the tile is marked ‘polished’ it is likely to be porcelain.
2. Check the price. Porcelain tiles generally cost around 40% more than ordinary ceramic tiles and could be even higher depending on other technical factors.
3. Try the spit test for water absorption. While you may not want to walk through Tiletoria spitting on tiles, if you turn the tile on its side and apply a little spittle to the edge, you will be able to tell if the tile is porcelain or ceramic. If it is absorbed into the tile within a minute or less it’s ceramic. On a porcelain tile, the liquid will remain on the surface in a shiny meniscus for a few minutes or until it evaporates.
4. Take a close look. Full body porcelain tiles carry the color and pattern through the entire thickness of the tile making them virtually impervious to wear and are suitable for any application. If the colour on the surface is the same through the cross section it is a good but not infallible indication that you are looking at a porcelain tile.
5. Compare the hardness. Ceramic tiles are softer and easier to cut than porcelain so if you are comparing two tiles the one that is easier to cut is probably ceramic.
6. Test the hardness. A more accurate way would be to actually test the hardness using a reference material.
7. Contact the manufacturer. You are able to request a laboratory test report from the manufacturer of the tile or ask a Tiletoria salesman for assistance. Porcelain is classed B1a with a water absorption of <0,5%.
Measuring tile hardness
Hardness is measured using the Mohs scale which rates hardness from 1 (talc) to 10 (diamond). Ordinary ceramic tiles will have a hardness of between five and six, whereas porcelain will have a hardness of seven or above. You can use the following commonly available materials to firmly scratch the tile. If the material leaves a distinct mark the tile has a hardness less than the test material:
Penny (a bronze coin) – 3.0
Knife blade (a good straight edged kitchen knife or penknife) – 5.0
Glass (a broken piece of window glass) – 5.5
Quartz (a sharp piece, available at new age lifestyle shops or a mineral scratch patch) – 7.0
Wondering which tile you should use?
Porcelain tiles are generally made by the dust pressed method from porcelain clay like kaolin, which results in a tile that is denser and more durable than ceramic tile. The finish is a finer grained and smoother with sharply formed faces. Glazed porcelain tiles are much harder and are more wear and damage resistant than non-porcelain ceramic tiles.
Remember that it is fundamental to ensure that you know what application you will be using your tiles for. If you are unsure, one of our friendly Tiletoria sales team members are always there to assist you.