Agora Commodities has managed to sell more than $10m-worth of gold and silver for bitcoin since it started accepting the cryptocurrency last year.

The firm points out that bitcoin gained more than 4000% in value last year, although that's not the company's primary focus, which is more on shiny, tangible commodities rather than digital currencies.

The biggest rush came in late 2013, as the price of bitcoin skyrocketed. Clearly, there were many speculators who decided to trade in their bitcoins for precious metals.

Agora Commodities is a relatively young company, but it is already the biggest dealer of precious metals for bitcoin on the planet. In addition to gold and silver, the company also sells platinum, palladium and rhodium.

The company sells a wide range of products, ranging from 1 kg gold bars priced at $43,000, to one-ounce silver coins priced at $21.

Bitcoin lovers can even combine their love of cryptocurrencies and precious metals with Agora's Silver Bitcoin Specie, a quarter-bitcoin piece priced at $23.50. No bitcoin included, of course. It features a handy QR code on the back and the design is rather nice, especially the binary string on the margin.

The only problem is that international shipping is quite costly, increasing the price of the purchase significantly. So, unless you plan to make a substantial investment in precious metals, it may not be worthwhile – especially if you were thinking about picking up a single coin as a gift, or a geeky conversation piece.

If all this talk of physical coins sounds familiar, don't worry, it should. Mike Caldwell, the entrepreneur behind Casascius has been minting physical bitcoins for a while. However, his efforts were curtailed last year, when the US Financial Crimes Enforcement Network (FinCEN) ruled that his activities were essentially 'money transmitting' and that he did not have a permit to carry out such services.

Caldwell then turned to minting unfunded coins, which feature private keys and can be stocked with BTC by the buyer. Caldwell describes them as "paper bitcoin wallets inside a coin container".

While physical coins aren't very practical, and they are essentially the opposite of what a digital currency was intended to be, they do look quite a bit more appealing (and durable) than your average paper wallet.