Jake Matijevic was found to be high in elements consistent with the mineral feldspar, such as sodium and potassium, and low in elements such as magnesium and iron.

BBC: Nasa's Curiosity rover finds 'unusual rock'

Compounded from violet-golden clay and a mixture of burnt feldspar, limestone, quartz and plant ash, the glaze is prepared from recipes that have often been handed down for generations by teachers or within families.

UNESCO: Culture