Japan, Ansei 1 Bu-gin Silver
This rectangular bar of silver is an actual coin that was issued by Japan ca 1859-1868. Later on they were replaced by round coins, but this coin circulated for 10 years. It weighs 8.63 grams and is about 150 years old.
There is also a chop mark to tell the owner that this was good silver and a real coin to be used. These are in very nice condition and would make a most interesting and important addition to your collection. Supplies are very limited.