The value of Gold or silver is mainly dependent on its purity as well as its quantity in carats. Determining the value of gold or silver is tricky since the values keep on changing based on world market prices. However, there are simpler ways of knowing the value of your gold or silver. Your buying price should always be your guideline. Since gold and silver does not depreciate, the current value should always be higher than the purchase value. You can weigh the gold or silver, then seek information from local gold traders about the cost of gold per carat, and then calculate the value of the number of carats you have.
If you have a lot of gold, banks and creditable financial institutions are good in determining the prices of gold bars. Just like stocks, the prices of gold also vary in day-to-day trade. When you know the weight of your gold in carats, you can easily calculate the value based on the current fair market price per carat. However, at times its face may determine the value of gold. A well polished bar might sell for higher even when it weighs lighter than an unpolished bar that weighs more. This is because gold is related to luster and shine and therefore the appearance matters a lot.
Since the value of silver or gold also appreciates with years, you could calculate a reasonable interest rate from the time you bought it and then compare the same with the current market prices of gold and silver. This can be a good guideline of determining the value when you want to sell you gold or silver.