DIA165mm, China

This beautiful blue beads are jade beads dyed with a technique which dated back to the Han dynasty.  Unlike today where a lot of  jade are dyed to imitate the perfect shade of green in order to fetch a better price, in the previous dynasties jade are dyed simply for a desired colour.  The material is treated almost the same as a piece of cloth.

According to the book Yu Ji (The Record of Jade) of the Qing dynasty jade can be divided into 9 Se and 13 Cai.
“Se” refers to the intrinsic colour of the jade;  still ocean black, indigo blue, moss green, peacock feather green, steam chestnut yellow, cinnabar red, clot blood purple, ink black, white as snow to lard.

The 13 “Cai” refers to the dye colour;
chestnut yellow from using earth with a darker shade when using rosin,
sky to sapphire blue from indigo,
peach red from lime,
coal black from mercury,
date red from blood,
parrot green from copper,
other dye colours include cinnabar red, chicken blood read, palm fiber purple, aubergine purple, pine cone green, ginkgo green, okra yellow, wine yellow, fish belly white, brown rice white, shrimp roe green, snot green.

Apart from the colour, the book also describe patterns, textures and even fragrant can be achieved.