What does BU mean?
Brilliant Uncirculated coins are of a higher standard than circulating and bullion coins. An entry-level collectable, like Proof coins, the dies used to strike Brilliant Uncirculated coins are polished and finished by hand.
The Brilliant Uncirculated blanks are machine-fed and struck twice. As a result, they are produced at a much quicker rate than Proof coins. They offer a good level of design detail, but have a lower definition than Proof coins.
Most Brilliant Uncirculated coins are struck in base metal, but they can also be issued in gold and silver.
What does legal tender mean?
Legal tender has a very narrow and technical meaning in the settlement of debts. It means that a debtor cannot successfully be sued for non-payment if he pays into court in legal tender.
In practice this means that although the silver UK coins produced by The Royal Mint in denominations of £5, £20, £50 and £100 are approved as legal tender, they have been designed as limited edition collectables or gifts and will not be entering general circulation. As such, UK shops and banks are unlikely to accept them.
What does proof like mean?
Proof coins are the highest quality commemorative coins. Their sharpness, detail and finish are unrivalled, making them perfect for collectors looking for highest levels of craftsmanship and detail.
The dies used to strike Proof coins are hand-finished to ensure that all imperfections are removed. Blanks are fed into the coin press by hand before being struck up to six times, at a lower speed and with less pressure than other finishes, to preserve the finer details of the design.
After striking, each coin is inspected for imperfections. The dies are cleaned with air between each coin to ensure that no marks or imperfections are caused during striking.
As a result of this extra care and attention, no more than 50 Proof coins can be struck within an hour. Proof dies are also regularly reworked to maintain the quality of the finish. Each Proof die may only strike a few hundred coins before it has to be repolished.
Proof coins are struck in platinum, gold, silver and base metal editions.