If the situation is as described with regard to buying and selling worked gold, then dealing with it in this manner is haraam if the price which is paid in instalments for worked gold is in currency, either gold or silver, or cash that is now used in their stead, because this is riba al-nasa’ (i.e., riba paid for delay in payment). This transaction combines riba al-fadl (i.e., riba paid when wealth exchanged is of the same type but the quantity is different) with riba al-nasa’ if the payment is made in the same type of wealth as what is bought, e.g. if both are gold but their weights differ, and payment is made in instalments. 

And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote. 

Standing Committee for Academic Research and Issuing Fatwas 

Shaykh ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan, Shaykh ‘Abd-Allaah ibn Qa’ood