Espresso Cups are made from Ceramic or Glass and in some cases Metal.
Ceramic is a hard wearing material that will give many years of service and during the high-temperature firing process will retain it’s strength and has the bonus of being inorganic (no hydrogen or carbon atoms) and non-metallic (contains no metals)
Ceramics fall into four categories Stoneware, Earthenware, Bone China and Porcelain, differences between ceramics depend on the clay used and firing temperatures.
Stoneware is very tough and inexpensive with higher opaque properties than Bone China and Porcelain and is the standard ceramic for most Espresso Cups. Stoneware is kiln fired at 1300 degrees and consists of 60% fireclay, 20% ball clay 10% feldspar and 10% silica.
Earthenware is the original ceramic it’s cheap to manufacture and is not as robust as the other three ceramics and is more prone to chipping. Earthenware is fired at 1100 degrees and is made up of 30% fire clay, 30% ball clay, 30% common surface clay and 10% silica.
Bone China originated in London in the mid-1700’s and is made from bone ash which comes from calcined animal bones, a very strong and durable ceramic which makes the production of thinner Espresso Cups possible. A bone China mix is fired at 1200 degrees and consists of 50% Bone ash, 25% china stone and 25% kaolin.
Porcelain originated in China and is a tough high strength ceramic. Porcelain is fired at 1300 degrees and consists of 25% feldspar, 25% ball clay, 25% Kaolin 25% silica
Glass Espresso Cups are very popular in the UK market they are made from borosilicate or soda lime glass. Both types of glass are mainly silicon dioxide borosilicate has an 80% content while Soda Lime has a slightly lower 74% content, other materials include sodium oxide, calcium oxide, and aluminium oxide with small traces of chlorine, sulfur trioxide, titanium dioxide, magnesium oxide, and iron oxide.