Gold, in grams
Balances in grams and cash
In a gold jewelry store, people owe each other metal as often as money. Each customer has a cash ledger and a separate gold account. When a customer deposits metal, the credit can carry labour/kaat in ratti, per 10 g or as a percentage, and the gold received goes into your raw metal stock at its physical weight.
Vendors work the same way, on their own wastage and making terms, so you always know how many grams are out with whom.