To add Precious Metals, select Add Holding, then Investment -> Commodities (Holding Class) -> Precious Metals (Holding Type).

First, you need to give a name to your Basket of metals, or select any of your existing ones. 

In the field marked Metal, you can search for the specific precious metal (or Position) you want to add, and if there is a public price source for it you will never have to update its valuation again. 

Please note that for Precious Metals we use the 3-month future contract price, as a proxy for the spot price.

When you add an Investment with available public prices, Exirio will automatically suggest a transaction price (the closing price of the day the transaction was executed, or yesterday's closing price if you are adding a transaction today), which of course you can edit and change into the actual price at which you have traded.

You can also choose to track your investment in physical precious metals manually as a single Investment without a breakdown of the single positions: in this case, select Add Holding, then Investment -> Commodities (Holding Class) -> Other (Holding Type).