In the late 1850s gold was discovered near Denver. Within a few years Georgetown, Central City, Black Hawk and other towns to the west of Denver became thriving communities.
Various business enterprises, including local saloons, were in the habit of accepting pinches of gold dust. To remedy the situation and provide a convenience for local miners, several assayers and coiners began business. It developed that the firm of Clark, Gruber & Co. was to become by far the largest. However, there was apparently room for a number of competitors in the field.
The Denver City Assay Office is a Colorado enigma. An extensive series of patterns was prepared, as the following offering indicates. However, no specimens are known to have been actually struck in gold. Was the Denver City Assay Office a going operation, or was it one of many dreams, possibly conceived in the East but never brought to fruition? Although Donald Kagin and others have assigned denominations such as $5, $10, and $20 to its various pattern issues, no examples are known which have a denomination expressed as part of the inscription. Indeed, one type of so-called $5 has the inscription "FIVE TOKEN," which we believe to be
hardly the type of inscription that would be put on a piece intended to be struck in gold and circulated at a value of $5. (By comparison, the Clark, Gruber & Co. coins of the same era and same city of issue plainly stated the denominations in dollars.)
Certain of the pieces bear the word "KRAATZ," which may have been the name of the person once associated with the operation, although there is no confirmation of this. Donald Kagin quotes a recollection of Milton E. Clark (of Clark, Gruber & Co.) in which Clark stated that he "had a slight remembrance of an assaying firm contemplating the establishment of a gold coinage business in Denver in 1860, but that its plans did not materialize."
These pieces were first really called to the attention of numismatists by J. W. Scott in 1893, who listed four different pieces and noted that they were struck by the Cord Brothers.