Nomination facility is available in banks, where one must nominate family member/s to receive the proceeds of his account after his death.  Nomination must be done.  In case the no nomination is registered in the account, the familiy members have to perform so much legal procedures, fill so much documents,  and all the family members need to receive the payment collectively so all are required to be present at the time of payment in addition to all the legal formalities already completed.  But in case the account is nominated, the nominee easily will receive the payment for and on behalf of all the family members of the family members.  Very little formalities in nominated account.
If the gold or other precious items kept with a Bank in it's locker, again if the nominated account it is, the procedure will be the same as above.
In case of coins the password may be kept in a locker of a Bank and must be informed to wife/husband or children advising them to run the account with the password available in the locker.  The password should be kept in physically noted format on a piece of paper and also in digital format in pen drive etc.