At the time of the Prophet (peace be upon him), two main currencies were in use in Arabia: Dirham and Dinar
The Dinar
The dinar was a gold coin. During the Prophets era and also during the Rashidun Era the dinar was likely based on the Byzantine solidus. Scholars differ on the exact weight but it was generally between 4.25 and 4.5 grams. Formal dinar officially minted by Muslims is said to be in 77 AH (Umayyad Era) during the reign of Abdul Malik b. Marwan.
The Dirham
The dirham was a silver coin. During the Prophets era, silver was more prevalent in Sassanid Persia. The quality and weight was variable. Some were the same weight as a dinar, some 7/10 and some as low as 5/10 of a dinar. During the Reign of the eminent Sahabi Umar Faruq (may Allah Almighty be please with him), it was standardised to 7/10 of a dinar.
Conversion
In terms of value 10 dirhams equaled to 1 dinars.
In terms of weight 10 dirhams equaled to 7 dinars
