High-value German coins of that period usually included the name of the issuing state or other jurisdiction within the Empire; that can greatly affect its value. See if you can find one of these words on the coin (I know it's a long list) and post a new question with that information:
Anhalt
Baden
Bayern
Braunschweig
Bremen
Hamburg
Hessen
Lippe
Lübeck
Mecklenburg
Oldenburg
Preußen
Reuß ältere
Reuß jüngere
Sachsen
Sachsen-Altenburg
Sachsen-Coburg
Sachsen-Meiningen
Sachsen-Weimar
Schaumburg-Lippe
Schwarzburg-Sondershausen
Waldeck und Pyrmont
Württemberg
You should have your coin evaluated by an expert in European issues. According to sammler.com, a major German collectibles site, it could be moderately rare. Values as of 03/2012 are
Moderately worn: €220
Slightly worn: €420
Uncirculated €650
Only 29,000 were struck. They were issued by the state of Hesse-Darmstadt which was semi-independent at the time.
As far as I know, the 10 Mark piece has a weight of 0.1152oz. At today's price of $1,736.45 (Oct. 15, 2012) it is worth at least US$200, to a collector it would be worth more (depending on condition). In very good condition, it could fetch $350-$400.
Deutsches Reich = German Empire
Germany
ANSWER In 1804 there was no German Empire (Deutsches Reich). Thank you I realise now we have made a mistake and it is 1894
Deutsches Reich, or the Third Reich.
orange
1 german reich is worth £2.09 or $3.33
The Third Reich
$345.00 u.s.
.22 cents us
50.00
Deutsches Reich Gebrauchs Muster - registered patent in Germany.
20 dollars if its mint