valuaion of jewellery

I would like to know the views of the learned members in respect of the valuaiton of the jewellery. My client has got jewellery valued in 2006 june at 34 lacs and has been making adjustments as specified vide CBDT circular in respect of additions/deletions.

I would like to know while applying rate of gold for jewellery valuation purpose, why factor of 83.5% is taken. Is it written somewhere.

In readyreckoner, i foudn a line wherein it says that in case of bangles a discount of 12% is to be given and in others case 21%

Would like to know wt is the actual law on valuation as on date. please explain.