Regular jewelry stores have regular invoices and sales receipts. And the most important warranty. That is, quality assurance. These must be available. If you don't ask. Generally, pure gold has a logo of 999. If you are afraid of falsehood, you are afraid of impure. You can only watch him burn when you go to the processing point in the mall to check the gold. Pure gold will not burn, and gold, a common currency, will certainly preserve its value.