We are continuing our Pigment of the Month series with another autumn-appropriate color, a rich brown called Sienna. This natural pigment is one that dates back millennia when it was used in some of the first known cave paintings. Sienna is made from clay composed of iron oxide and manganese oxide, two minerals that are common in soil. In fact, Sienna gets its name from the Italian ‘terra di Siena,’ meaning “earth of Siena.” Siena, a small city in the region of Italy known as Tuscany, also used to manufacture the pigment. Other names to which this pigment is referred are terra rossa (red earth) or terra gialla (yellow earth).