It has gathered its fortune through the tools of modern finance, but now Islamic State (Isis) aims to mint its own coins.

The move is reportedly the brain child of the Isis leader, Abu Bakr al-Baghdadi, who has personally overseen the design of gold, silver and copper coins of the Islamic dinar to be used in his self-declared caliphate – as soon as the terror group can locate a mint and enough precious metals.

Isis has released designs of the coins and a breakdown of denominations. It claims the currency will free Muslims from a financial order that has “enslaved and impoverished” them. But it isn’t totally eschewing the mainstream economy, acknowledging that each coin’s worth will reflect the metal’s value on commodities markets.

Gold will have two denominations, silver three and copper two. With the Isis caliphate not recognised anywhere in the world, the currency will have no value outside the swath of eastern Syria, and western and central Iraq under its control. And those who dare to trade with the group would run the risk of money-laundering and terrorism charges.

Until now, oil purchases from the fields controlled by Isis have been carried out using euros, dollars and Iraqi dinars, and such dealings are unlikely to stop. The paper currency of Isis’s mortal foes has helped transform the group from the scattered remnants of the Iraq civil war to the most cashed-up and capable terrorist organisation in the world.

Iraqi intelligence officials say it looted close to $500m (£320m) in cash from Mosul’s banks alone when it overran the city in June. In addition, kidnaps for ransom payments are thought to have brought in $25m and antiquities smuggling more than $38m. Until recently, oil had been the group’s main cash cow, with daily sales of $1m to $4m for more than a year.

Isis has said it aims to revert the centre of the region to the type of lifestyle lived during the prophet Mohammed’s reign. It has been choosy, however, about which trappings of the post-industrial world and information age will have a place in its back-to-the-future world. The internet is much prized, as is electricity, advanced battlefield weapons and cars.

“Even within the believers, this [currency] will be a stunt,” said an Isis member who returned recently to Lebanon from northern Syria. “If they want people to buy eggs with new coins, then they will. But the real business will be done with real money.”