I have this coin from the Islamic Samanid empire which is as large as a US silver dollar and have been researching it while staying at home.
Samanid Multiple Dirham Nuh II Kurat (No date)
Silver, 44 mm, 11.17 gm
Ruler: This coin was minted under the rule of Emir Nuh II whose reign was AH 365 to 387 (AD 976-997).
Mint: Kurat, located near Fayzabad, Badakhshan province, northeast Afghanistan
Field: Islam Kalima "There is no god except Allah. He is Alone. There is no partner to Him"
Ring outer: Quran Surah 30:4 "Of Allah is the Command from before and from after and on that day the believers shall rejoice in the victory of Allah"
Ring inner: In the name of God, this dirham was struck in Kurat
Ring outside top: Ayyar (warrior)
Ring outside bottom: Jayyid (good)
Field: Allah / Muhammad / Messenger of Allah / Nuh, ibn (son of)
Ring outer: Quran Surah 9:33 "Muhammad is the messenger of Allah. He sent him with the Guidance and a religion of the truth in order that he might cause it to be bright over the religion, although the polytheists disliked it"
Ring outside top: three dots
Ring outside bottom: one dot
These coins, called multiple dirhams, were minted in the 10th century AD in northeast Afghanistan in an area located on the north slopes of the Hindu Kush mountains where a lot of silver was discovered and mined.
A situation developed similar to the 1850's when the US mints began minting larger size gold coins to accommodate the gold coming from California.
The ultimate customer for these coins were the Scandinavian Vikings via Russian trading posts, and large hoards of Samanid dirhams have been found in Sweden and Norway.
Could this coin be the first crown-size silver coin minted?