Please post a new, separate question with the coin's date. Without that information it's not possible to estimate a value.
It is a German Deutsche Mark.
The German 1 Mark coins from that era were actually made of copper-nickel, and the highest collector's value would be around $4, if it's still in uncirculated condition.
Cash Value : about half a Euro. A one-mark German coin has a value based on the old exchange rate with the Euro. In 2002, the old Deutschemarks were invalidated as legal tender, but marks were exchangeable at the rate of 1.95583 Marks per Euro, which was set in 1999. So the coin may have more or less value as a collectible than if redeemed for Euros.
It was the German Mark, also known as the Deutsche Mark.
Deutsche Mark preceeded the Euro as the currency in West Germany
Germany used the Deutsche Mark as its official currency before adopting the Euro in 2002. The Deutsche Mark was also used in some German territories, such as West Berlin, before reunification in 1990.
what is the value of the German mark coin with horse on back dated 1923
The Deutsche Mark was not used in 1863 (individual German states issued their own coinage, although copper small change was issued jointly at times). On the assumtion that you meant the 1963 deutsche mark coin, it depends on the mintmark (found below the eagle's tail) and the coin's condition. Broadly, it is worth about US$1.00 to 1.50 in circulated condition, $10 to $15 in Extremely Fine, and $110 to $200 in Uncirculated condition, with the "D" mintmark at the low end of the range, the "F" and the "G" in the middle, and the "J" at the high end of the range.
the deutsche mark
Deutsche Mark
Deutsche Mark
That really depends on the year the coin was minted and the condition of the coin.