old gold manufacturing in gst

Dinesh Banthia (32 Points)

11 April 2019  
Hello,
we are a Retail Jewellers
Before gst when our customers bring there old gold for remaking we charge vat tax only on there excess gold.
But since gst is implemented we stop customer manufacturing. Now we are charging on full valuation as a new purchase. Hence there old gold is converted to URD purchase as now there is no tax . Here has to bear tax again and again.
So please can you help into this matter if there any clause in gst to save tax & once again we can start
customer manufacturing.
Thanks! Dinesh Banthia