What is celadon pottery?

In China.

The earliest shards found were from the Eastern Han Dyansty tombs in Zhejiang (25-220AD).

Iron reduction fired, high fired celedon is from the Northern Song Dynasty (960-1127).

It is in dispute where the term came from. Some say it is from the Arab name Saladin who sent 40 pieces of celadon pottery to a leader in Syria in 1171.

The second idea is it came from Sanskrit for green stone--sila and dhara.

The last idea is it came from a French character of a shepard in the romance, L'Astrée (1627), who wore pale green ribbons.