The proclamation of faith on one side states: "There is no god but God alone. He has no partner".

The other side states that "Muhammad is the Messenger of God"
Roughly $200 worth of gold if melted down.  But it's in mint state and struck by hand somewhere in the middle east, probably modern-day Iraq, almost 1,300 years ago in 773-774 AD.
 
Abū Jaʿfar ʿAbd Allāh ibn Muḥammad al-Manṣūr (/ælmænˈsʊər/; Arabic: أبو جعفر عبد الله بن محمد المنصور‎; 95 AH – 158 AH (714 CE – 6 October 775 CE) usually known simply as by his laqab Al-Manṣūr (المنصور) was the second Abbasid caliph, reigning from 136 AH to 158 AH (754 CE – 775 CE) succeeding his brother al-Saffah (r. 750–754). He is known for founding the 'Round City' of Madinat al-Salam, which was to become the core of imperial Baghdad.
 
Modern historians regard Al-Mansur as the real founder of the Abbasid Caliphate, one of the largest polities in world history, for his role in stabilizing and institutionalizing the dynasty