The Many Wonders of Fe₂O₃

Bengala: History's Most Ancient Coloring

Bengala is just one type of Iron oxide. The name originated from the Bengal region of India, where natural bengala, or hematite, was produced. India is still a producer of hematite, limonite, and magnetite−all of which are used as colorants. In the worldfamouse caverns of Ajanta and Erolla, paintings in red, yellow, and black were found.
These were drawn around 3,000 years ago by primitive artists using natural oxides. The paintings indicate the long history of iron oxide's use as a coloring agent. It is believed that ancient people grinded the ore into powder, diluted it with water, animal fat, or natural resin, and created a starchy substance use for painting. These precious treasure of human culture could not have been preserved till today without the benefit of iron oxide, which is chemically stable, preservative in character, and abundant in the natural environment.
The color of iron oxide ranges from red to black or yellow, depending on the crystalline structure of its iron component. The range of color, afforded by the combination of differently structured iron crystals, is just one of iron oxide's many appealing aspects.

Kakiemon's "red" also came from iron oxide

Bengala has been used in Japan since ancient times. Moreover, it was one of the materials used to draw the wall paintings found in the horizontal decorative tombs of Japan's Kofun (Ancient Tombs) Period. The bengala used in these paintings was made from the natural iron oxide contained in red soil. Temples, Buddhist figures, and other formative arts from the Asuka and Nara periods−which were profoundly influenced by the Buddhist cultures−also employed various coloring agents. It is said that bengara red was commonly used along with other types of red.
The potter, Kakiemon, was said to be enchanted with the glow of persimmons against the sunset of autumn. He successfully recreated this persimmon color using an overcoat made from fine, uniform particles of iron oxide. In fact, this ancient method of color formulation, in which iron oxide is processed into fine particles, opened the door to the creation of artificial colorants based on iron oxide. The first artificial iron oxide in Japan was produced in Okayama Prefecture mining town of Fukiya approximately 400 years ago, when local people made a iron sulfate called ro-ha from magnetic pyrite using a Chinese technology, and roasted it to make their paints.

Kakiemon is a very famous ceramics artist.