Assertion: mirror | /r/MadeOf | metal alloys
Facets:
Source sentences:
text: In China mirrors began to be made from metal alloys, a mixture of tin and copper called speculum metal that could be highly polished to made a reflective surface as well as mirrors made of polished bronze.
text: In China mirrors began to be made from metal alloys, a mixture of tin and copper called speculum metal that could be highly polished to made a reflective surface as well as mirrors made of polished bronze.