I just picked this one up for my Sixpence type set. The 1821 is a one year type and I particularly like the reverse design elements, I'm really not sure why they didn't keep this design going as I much prefer it to the later reverse.
This nice dark "bronze tanned" toning is especially nice on a Mint State coin. I have a 1951 (first year) Japan 10 Yen coin with similar color.