Question About A Golden Ducat

Do you know the name of the book?

Looks like a table of Jewelers marks - hallmarks etc.

Each of the 6 punches corresponds somewhat roughly with the Karat system of gold used worldwide.

As we all know pure gold is 24 karat. That is 24/24 or 1000 fine and it is never used for jewelry because it is too soft. There is however a 24K stamp and likely would be used on an original coin because it is the closest most jewelers could get in the late 1800s.

The purest gold typically used by jewelers is 22 karat. That is 22/24 or 916.66 fine. The A1 stamp says 920 a bit high but a good approximation.

The next common standard is 20K. That is 20/24 or 833.33... fine. The A2 stamp 840 (?) is therefore an indication of 20K. Again a bit high.

The next jewelers standard is 18K which is 18/24 or 750 fine which matches A3 exactly.

A4 584 corresponds with roughly 14K which is 583.33... fine.

A5 500 is 12K which is 500 fine exactly.

There is no 10K recorded in this system which the US and European standards accept as the lowest Karat gold that can actually be referred to as "gold". Ten Karat gold is normal for gold fillings and wedding rings due to the wear normally associated with those uses.

A6 330 is roughly 8K gold 333.33 fine. Once again slightly low.

So the chart is clearly a jeweler's chart. It would normally be used to mark gold content of items made by the jeweler.

Perhaps it proves the origin of a "counterfeit" as Bulgarian which would be a collectable variety. Or it may have been a jeweler's attempt to classify the coin by purity.

So, the jeweler was either in error about the assay or he was a counterfeiter. Interesting. VERY Interesting for a counterfeit collector like myself.

The coin should be XRF tested to be sure.