Entry for melting old gold in tally

kartikgowadia (proprietor) (63 Points)

24 November 2019  
in jewelry business opd gold is purchased from the customer, after that it is melted and converted into pure gold

say 22 carat of old gold purchased (qty - 100 gms, amount paid-400000) now after melting i get 91 gms of 24 carat gold how am i to pass such entry in tally??