What Are Ceramic Tiles Made Of? | Clay, Minerals & Firing

Ceramic tiles are made primarily from clay mixed with minerals like feldspar and silica, then fired at high heat to harden.

Ceramic tile starts as a mixture dominated by clay, but the recipe is rarely just clay and water. The standard body combines plastic materials—clay, kaolin, and bentonite—with non-plastic minerals such as feldspar, quartz, talc, and limestone. These ingredients are ground, shaped, and fired at extreme temperatures to create the hard, durable surface you walk on. Understanding what each component does explains why tiles differ in strength, color, and water resistance.

The Core Ingredients Of Ceramic Tile

The composition of a ceramic tile breaks down into two main groups: plastic materials that give the body shapeability, and non-plastic minerals that control strength and firing behavior. Clay provides the plasticity that lets manufacturers form the tile, while feldspar acts as a flux that lowers the temperature needed for firing.

Silica, or quartz, improves thermal stability and reduces shrinkage during the drying and firing stages. A sample composition for a standard tile body, per technical ceramics sources, includes clay at 50–70%, feldspar at 15–25%, and fireclay at 10–20%, with kaolin making up 0–10% depending on the desired whiteness. Exact percentages vary by manufacturer and tile type, so treat any single recipe as a representative example rather than a universal formula.

What Each Material Does In The Tile Body

Each raw material earns its place in the mix by performing a specific job during forming, firing, or finishing. Clay and ball clay deliver the plasticity needed to shape the tile. Feldspar melts early in the firing cycle, binding the other minerals together into a glassy phase. Silica adds structural strength and controls how much the tile shrinks as it dries.

• Clay, kaolin, fireclay: supply plasticity, binding, and shaping ability; kaolin also contributes whiteness to the fired body.
• Feldspar: a fluxing material that forms a glassy phase and lowers the firing temperature, saving energy and improving density.
• Silica or quartz: boosts strength and thermal stability while controlling shrinkage.
• Talc, dolomite, limestone: modify fluxing, opacity, and firing behavior in specific formulations.
• Pigments and glazes: provide color, surface finish, and processing control on glazed tiles.

The glaze layer sits on top of the clay body and is a separate material system. A glazed tile therefore has two distinct structures: the inner fired clay body and the outer glassy coating that carries the color and finish. Unglazed tiles rely entirely on pigments mixed into the body itself.

Porcelain vs. Standard Ceramic Formulations

Porcelain tiles use finer, more refined clay blends than basic ceramic wall tiles, which is why porcelain is denser and more water-resistant. One technical source notes that traditional ceramic tiles may consist of roughly 70% porcelain clay, 20% porcelain stone, and 10% quartz. White-burning tile bodies follow a different split, using 30–40% clays and kaolins, 40–60% feldspar, and only 0–10% quartz, with small amounts of dolomite or calcium carbonate as additional fluxes.

The practical difference shows up in performance. A denser porcelain body resists moisture better and suits floors, while a softer wall-tile body with more feldspar fires at lower temperatures and works fine on vertical surfaces that see little wear. Manufacturers adjust the recipe for the tile’s intended job, so two tiles that look similar can have very different internal compositions. If you’re comparing options for a specific space, our roundup of the best ceramic tiles lists top-rated choices for floors and walls alike.

How Ceramic Tiles Are Manufactured

The manufacturing process transforms raw minerals into a finished tile in four stages. First, manufacturers select and proportion the raw materials—clay, feldspar, silica, and any additives—according to the target tile’s properties. Next, the materials are mixed and ground, often in a ball mill, into a uniform slurry or body slip. The slurry is then formed into tiles, dried to remove moisture, and fired at very high temperatures so the minerals sinter and harden. Glazed tiles receive their surface coating before the final firing pass.

The firing step is what creates the ceramic structure. Without kiln temperatures high enough to vitrify the clay and melt the feldspar into a binding glass, the tile would remain brittle and porous. This is also why the exact chemical composition matters: a body with too little flux won’t densify properly, while too much can cause warping during firing.

Because formulations differ by manufacturer and product line, the only way to know a specific tile’s exact makeup is to check that manufacturer’s own technical data. The ingredients above cover the standard recipe families. Roughly 50% of a typical ceramic tile body may be clay by dry weight, but that number shifts for porcelain, white-burning, and specialty products. For most buyers, what matters is the finished performance rather than the precise mineral breakdown. ScienceDirect’s ceramic tile engineering overview confirms these material groups and their functions in detail.

The table above reflects a representative standard body. Porcelain and white-burning formulations shift these ranges considerably, so always check the manufacturer’s spec sheet when a tile’s exact density or water absorption matters for your project.