Tube bangles from India may be filled with copper, brass or other material, what might look like  a very heavy piece of jewelry you may find is full of nothing material, just to add to the weight of the item. We have seen this many times, some customers know this is done to their items, others have had it done to the tube bangles to make it stronger. In some case’s the customer is not aware. We took in some bangles as scrap that had copper filling, there was only 8.8 grams of gold on them just a thin layer, seller did not know they where filled with copper.