There are two types of mosaic tiles. One is composed of tesserae and the other is made of pebble mosaics. It should be noted that neither is any type of design or simply an aesthetic pattern made with colours and other treatments. There is a type of mosaic tiles that can be ceramic, vitreous or porcelain among other materials wherein the pattern emulates the kind of intricate detailing and grandeur of the traditional variant of such a type of flooring. These are simply designer tiles. Even if brands use the term mosaic, it is not so if there is a large or small slab of a particular material.
Mosaic tiles must contain stone and glass. The best mosaics have a fine combination of stones and glasses, of varying colours and hence the resulting product is a work of art. There are mosaics that are made of only stones. These are usually referred to as floor mosaics. Small pieces of one or more stones are used to make pebble mosaics. These are more common as a flooring material. The use of stones and glasses is more common for mosaics on the walls. This does not mean glasses are not used in floor mosaics.
Since stone and glass are both a generic classification and there are many types in both categories, you must explore what is actually in a mosaic. You should find out the exact composition of mosaic tiles. This is important from the perspective of cost. You should not pay unnecessarily for something that is not of the quality you expect it to be. You should also know the composition to ascertain the manner in which the tiles need to be cleaned and maintained. Lack of awareness can be detrimental to the tiles and affect the return on investment.