A significant component, inclusion or trace in the material of which an object or specimen is made. This could also include a patina or corrosion product which has developed on an object and is of sufficient significance to require documenting.
How to record
Use a single term, without punctuation or capitalisation. Maintain a list of standard terms. The organisation should decide whether to use chemical abbreviations or full names, eg Cu or copper
shell tempering; carbon; textile; mineralised
One or more times depending on how many material components are needed to record an object. Only significant components of objects that have undergone scientific examination and analysis should be recorded.