Some anthropologists that have studied the presence of a remarkably thick blue layer found at the beginning of the 20th century at the bottom of the Sacred Well at Chichen Itza, say that  this blue was the color of sacrifice for the ancient Maya.

They used this pigment to paint human beings blue before they were put on an altar and had their beating heart cut from their bodies. Human sacrifices were also painted blue before they were thrown into the Sacred Well or Sacred Cenote at Chichen Itza.

This blue, known as Maya Blue was also used on murals, pottery, copal incense, rubber, wood and other items across Mesoamerica from about A.D. 300 to 1500.

This indestructible pigment has puzzled scientists for years because of its unusual stability properties. Its color persists in one of the world’s harshest climates, age, acid, biodegradation and even modern chemical solvents. Actually, it has been called “one of the greatest technological and artistic achievements of Mesoamerica.”

Several studies have found that Maya Blue can be created by heating a mixture of palygorskite with a small amount of indigo. They were fused together with heat by burning a mixture of copal incense, palygorskite and probably the leaves of the indigo plant. Then the sacrifices were painted blue and thrown into the Sacred Well.

It is believed that these sacrifices were dedicated to the rain god “Chaac” in the form a bright blue color since rain was critical to the ancient Maya of northern Yucatan. Offerings to “Chaac” had a great symbolic value and ritualistic significance, which hopefully would bring rainfall and allow the corn to grow again in the bad seasons.