There were no Morgan silver dollars minted in 1804. The first year of mintage for them was 1878.
Please check your coin again. It's either not a dollar, not a Morgan-design dollar, or not from 1823. Morgan dollars were minted from 1878 to 1904 and in 1921. No US silver dollars were made for circulation from 1804 to 1835 inclusive.
Please check again and post a new question. No circulating silver dollars were struck between 1804 and 1835 inclusive, and the Morgan name applies only to silver dollars dated 1878-1904 and 1921 that were designed by G. T. Morgan.
This is NOT an original 1804 silver dollar. The value is only worth what the metal is worth. If it's made out silver it will be worth more than if it just has a silver plating with some like a stainless steel core.
The only dollar coins that sell for over $1M are 1804 dollars.
Morgan dollars were minted from 1878 to 1904 and in 1921. "1804" dollars carry a Liberty Head design were actually minted in the middle of the 19th century to make a complete set of 1804-dated coins for presentation to the King of Siam. Please see the Related Question for more information.
Morgan dollars were minted from 1878 to 1904 and again in 1921. No US dollars were minted for circulation from 1804 to 1835.
If it's a fake, it's worth little to nothing.