Mars Violet is a modern term given to the dark violet synthetic reds made during the early 20th century and up to today; but a natural version of this color has been used since antiquity.
The clays that make this violet colour were always very rare compared to other natural iron oxides and it is not until Greco-Roman times that it is commonly seen in art. The Latin name for the color was Caput Mortuum, which literally translates as ‘the head of the dead’ and probably refers to a belief that it is similar to the colour of blood in corpses. Despite this macabre name it has been a well-liked pigment whenever it has been available because it extends the range of earth colors into the violet range.
Chemical Description: Synthetic iron oxide
Pigment Number: PR101
Lightfastness Rating: ASTM I
Pigment Opacity: Opaque
Paint Opacity: Opaque