Upvote:1
Re. the Chinese writing style, it turns out this particular style is called "Nine-folded seal script" (九叠篆) and first got popular during the Song dynasty in China, first appearing on coins in the 11th century. Note that this particular coin exists in a number of versions, from very readable to very stylized.
This means that if these two writing styles are related, their relation is older than the Ilkhanate or the Yuan dynasty (as stated in the question, the Square Kufic script seems to have been invented in the 12th century). I do not think it is entirely implausible that they are related, but it is also quite possible that they were developed independently from each other.
It might also be worth noting that the creative process is different for the Iranian and the Chinese writing. While the Iranian style is filling up the blank space with lots of simplified writing, the Chinese style is filling the blank space by making the characters more elaborate, e.g. by turning 王 into
or 理 into
Upvote:5
I can speculate about one possible relationship between the two styles.
Your Persian examples include square seals of Oljeitu and Ghazan.
Ghazan was born 1271 and ruled from 1295-1304.
Oljeitu was born 1282 and ruled from 1304 to 1316.
At that time the Ilkhans were more or less the vassals of the Great Khagan of the Mongols. Since 1271 the Great Khagan of the Mongols was also the Huangdi of the Yuan Dynasty of China.
If those seals were government seals of Ghazan and Oljeitu they might have been made in China and sent by the Great Khagan to the signify appointing Ghazan and Oljeitu to the position of Ilkhan. In which case the writing on them would be in either Chinese seal writing or the Mongolian script.
If the seals were made in Iran they might be in the Persian, Arabic, Mongolian, or Chinese language, possibly written in the square kufic script.