Hats are an important accessory in Chinese dress and an official was never seen without his hat outside his private quarters. Hat finials were worn by the nine ranks of high ranking Chinese officials during the Qing dynasty (1644-1912) to differentiate between the ranks, a practice governed by regulation.
Finials of this type were introduced in 1727 to be worn on less formal occasions (The type of finials reserved for formal occasions were tall, more eleborate and bejewelled). They were known as 'knobs' or 'buttons' and were fixed to the apex of the crown of the hat by a metal screw which passed through a hole in the hat. The colours and material from which the 'sphere' was made denoted the rank of the wearer. Glass became acceptable from the 18th century in place of semi-precious stones both to save expense and because glass itself was highly prized.
The ranks denoted by the finials are as follows (according to revised regulation in 1727);
First rank: round jewel of red clear Peking glass
Second rank: oval jewel of pink porcelain glass
Third rank: oval jewel of clear blue Peking glass
Fourth rank: round jewel of lapis lazuli
Fifth rank: round jewel of clear colourless Peking glass
Sixth rank: round jewel of opaque white Peking glass
Seventh rank: Top round jewel of gilt copper
Eight rank: round jewel of gilt copper
Ninth rank: oval jewel of silver (Circa 1790, After 1800 Ninth rank used a gilt copper jewel)