The UK's Royal Mint launches the country's first £20 coin next month.

"For just £20 you will receive a beautiful silver coin that is legal tender, and so prestigious that you will want to keep it as a collectable!" reads the information on the Royal Mint's website.

"Your £20 coin has inherent, lasting value," it adds.

Which might lead you to believe that buying one of these, admittedly beautiful, coins ahead of their October 31 release could be a nice investment.

Not a bit of it.

Firstly, buyers will already be starting at a disadvantage: the coin contains just £8-worth of silver content, at current prices.

More importantly, collectible coins like this one that are made to be collectible, generally aren't sound investments.

This one is no different: with a production run of 250,000 there are simply too many of them to ever be "rare".

The Royal Mint will produce 250,000 £20 coins – far too many to interest investors

History will not be on your side if you're hoping to profit from them.

"Not since the 1980s has a Royal Mint coin gained in value, I doubt any dealer will give more than £8 or £9 for it," Richard Lobel from London coin dealer Coincraft told the UK's Guardian newspaper.

Look here instead

So what should you do instead? You could invest in silver, yet at more than 20% down on last year's average price, a watching brief may be the best bet on that front right now.

A better bet might be to invest in coins of real collectible value - numismatic items that are rare and much sought-after. Pieces that are backed by historical price gains.

The Knight Frank Luxury Investment Index reveals that rare coins were up 9% in value in the 12 months to the end of June, and 12.5% per annum over the previous 10 years.

It's why pieces such as this 1645 Charles I Carlisle besieged shilling we have for sale make such exciting diversification prospects.

It was one of just 3,460 shillings produced in Carlisle while the city was under siege from Oliver Cromwell's men.

Just a handful of those 3,460 remain today.

This is a coin that has rarity, history and desirability. Would you swap it for the new £20 coin?

You can view all our rare coins for sale here.

Thanks for reading,

Paul

P.S Just to add salt to the wounds, although the new £20 coin is declared legal tender, shops and banks will likely not accept it, I'm told.