The ceramic definition of faience is of a material that contains both clay and a silica compound, whether glass or quartz.

There are materials called 'faience' by the archaeological community which contain no clay but are composed of quartz particles or quartz and glass. Some are glazed, some not. They have been heated to varying extents. In some the quartz is partially melted, in some not. This may possibly vary within even a specific workshop, depending on how high the kiln temperature and how well maintained.

The existing terminology is very confusing, as it arose prior to a time when electron scanning micrographs and specific analysis by X-ray and laser technology were possible.

There is similar confusion about the inner compounds in many Chinese beads of the early Sarmatian (Spring-and-Autumn to Warring States) period. Analyses of these compounds have been undertaken only within the past 25 years or so. It is still unknown what the constituents of many types are.

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Snap