This is a 1911-1919 United Kingdom 1 Florin coin featuring King George V. The coin is made of 92.5% silver and is part of the KM #817 series. The obverse of the coin depicts King George V, while the reverse features the cross of crowned shields and scepters in angles.
The date on this particular coin has been worn off, so it is not clear if it is from 1911, 1912, 1913, 1914, 1915, 1916, 1917, 1918 or 1919. At first, I thought it was the second version of the coin, but on closer examination, I believe it to be the first version based on its design elements.
This is a highly collectible coin for numismatists and history enthusiasts. Please note that this coin may have some wear and tear consistent with its age. For more information on this ornate coin, please visit https://www.ngccoin.com/price-guide/world/great-britain-florin-km-817-1911-1919-cuid-1132689-duid-1326726