Table 1 Citations concerning ‘black earth’ in historic written sources

Unknown author

Use of many organic and inorganic blackish compounds such as lignite, bitumen, bituminous schists, graphite, pyrolusite and iron oxides.

[12]

Pliny the Elder

(…) “it is possible to obtain a black pigment from the earth”.

[13]

Cennino Cennini

“Black is a black stone, soft and the color is fat; I found a stone coming from Piedmont good to draw”.

[14]

Giorgio Vasari

A black earth called “terretta” (soft earth) which can be used a fresco painting is reported.

[15]

Unknown French author

“All earths and black stones can be used to paint a fresco and a secco”.

[16]

Unknown Spanish author

“Black earth comes from Germany, is a natural earth and the color is black-bluish”.

[17]

Unknown German author

“A black material which is light, similar to clay, earth, is used to draw; it is very easy to obtain a powder and, when washed, a black mud remains on the bottom”.

[18]

Wallerio J. Gotschalk

“Ochra nigra argillacea” (black ochre containing clay minerals).

[19]

Mouchon

“Venice black is good for fresco painting and better than the Rome black earth”.

[20]

Don Antonio Palomino

“Black earth, a mineral color, black, earthy, very important for fresco painting”

[21]

Tilloch

(…) “those earths called red, green, black or yellow are of an argillaceous-calcareous nature”.

[22]