Galleon

Galleon is the most valued coin of the wizarding currency. One Galleon is equal to seventeen Sickles or four-hundred and ninety-three Knuts. Galleons are made of gold.

Early history
By the mid-thirteenth century, Galleons were already in circulation in wizarding Britain.

In the 1260s, the Galleon had much more value than today: one Galleon at the time was equivalent to more than six-thousand six-hundred and sixty-six Galleons today.

Recent history
Today, the Galleon values much less than it did in the thirteenth century. One Galleon is equivalent to five Muggle pounds.

Fake Galleons
Galleons made of Leprechaun gold were common at Quidditch games where Leprechauns are the mascots for the Irish team. These galleons are occasionally in temporary circulation (they vanish a few hours after appearing), but goblin experts at Gringotts can differentiate them from real ones.

Rubeus Hagrid used Leprechaun gold fake Galleons at a Care of Magical Creatures class, while teaching students about Nifflers' ability to hunt for shiny objects like coins.

Hermione Granger fabricated fake Galleons for members of Dumbledore's Army as a means of conveying clandestine communication about the time of future meetings.

Ludo Bagman used Leprechaun gold to pay Fred and George Weasley after their bet resulting in them blackmailing Ludo with no luck.

Notes and references
Gallion Galeon Галлеон