Sundar, It is very hard to use gold as collateral because it is easily faked. As you noted you will need an appraisal, however I doubt a bank will accept jewelry. I am not really familiar with gold as security for golds, but I can tell you about gold assets in the futures markets from my fund days, and it may be able to help you.
In futures markets you can take delivery of gold however it is very difficult to use it. For example, if you take delivery of a gold contract, they will generally send it to a bank and you will highly discouraged to take it out, mainly because gold is so easily manipulated (Gold bars can be melted down and you can put some type of steel in the centre). If you do decide to take the gold out of the bank, in order to put it back into the bank it will have to get it appraised.
Thats the thing about gold, the important thing is the purity of the gold and jewelry is rarely pure because the softness of gold means you almost have to mix gold with another metal in order to make jewelry. However, something tells me you are not talking about gold bars, or are you?
FYI I am not an expert in gold, its just a few things I do know about it. The only experience I have with gold is in trading the futures contract.