Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. Most of these by tradition are measured in troy ounces of fractions thereof, but the mint also introduced metric coins measuring one kilogram of pure metal (they are actually fractionally heavier as a whole, to account for the small amount of other metal in the alloy).
The 1 kg gold coins are denominated as One Thousand Pounds (£1,000), although their intrinsic (bullion) value is much higher than their face value. The coins vary in design depending on the occasion (they are "one-year" types usually issued in parallel with smaller denominations with the same reverse designs).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art.
The 2017 Year of the Rooster bullion coins are part of the Royal Mint's Shēngxiào Collection - a coin series dedicated to the Chinese Lunar calendar.
As the mint says:
"For centuries The Royal Mint has drawn upon its unrivalled heritage, experience, and craftsmanship to evolve and meet the needs of an ever-changing market. In 2014 we struck the United Kingdom’s first Chinese Lunar coins, introducing a new series and a United Kingdom first. The Shēngxiào Collection, named to honour the Chinese zodiac, is a celebration of the UK’s diverse multi-cultural society. At Chinese New Year, gifts and tokens are exchanged, particularly the gift of money in red envelopes, symbolising good wishes for the recipient’s health, wealth and prosperity. These Lunar coins from The Royal Mint embrace this globally observed tradition, lending a unique British angle to an ancient tradition."
"People born in the Year of the Rooster are stable and think deeply. They are hard workers, open, truthful and loyal individuals, and take pride in their appearance. They are happiest when they are surrounded by others and love being at parties or any social gathering. They enjoy using their charm and magnetism, meaning that they are comfortable in the spotlight. Roosters are motivated in their careers which are a priority in their lives. They are hard-working, multi-talented and can deal with a variety of jobs."
The gold 1kg coins were issued boxed, in Proof FDC grade only. | 
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