Markets → Melt calculator values metal you have not catalogued — scrap jewelry, a coin you are thinking of buying.
Choose a Product or the Metal, enter the Quantity, Weight each and its unit, whether the weight is Gross or Fine, the Purity, and an optional Premium %. Choose Calculate.
It shows the fine metal, the melt value and the market value with premium apart — a coin's premium can dwarf its metal — and which spot price it used.