Does the 1870 Pilgrim Jubilee So-Called Dollar exist in brass - HK-15?
Zoins
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I like the Pilgrim Jubilee So-Called Dollars and recently posted a few of mine.
In looking up information on this issue, I learned that NGC is of the opinion that HK-15 in brass may not exist as all known brass specimens they encountered are actually be gilt-copper with the following. That being, we do have some photos of HK-14 and I'm wondering if these look like brass or gilt copper?
The medals are listed in the So-Called Dollar reference as struck in silver-plated copper (HK-13), copper (HK-14), and brass (HK-15). However, it is likely that no brass examples were made, as tests by NGC have found these to be gilt-copper. These have been designated as HK-15A. A few medals were made in solid silver (HK-13A), and NGC has also certified a single white metal (tin) piece that was 5mm thick (HK-15B). Of these, the silvered-copper variety is the most common, and these often exhibit dark and/or colorful toning.
Regarding thick planchets, my HK-15A Gilt Copper is actually on a thick planchet, similar to HK-15B. I'm not sure if Gilt Copper comes on regular and thick planchets.
Here's a HK-15 posted by @keets and my HK-15A. They look very different. Does the HK-15 look like brass?
1870 Pilgrim Jubilee HK-15 Brass
1870 Pilgrim Jubilee HK-15A Gilt Copper
This looks much more yellow in hand than the photos which have a slightly orangish color.
@keets's original post of this with lots of beautiful So-Called Dollars is in this thread:
Comments
the HK-15 posted above was originally in an NGC holder and crossed to PCGS, I suppose I have the tag somewhere. when did NGC change horses on this?? I suppose the only way to tell is a specific gravity test.
I'm not sure when they made the decision but the NGC article is from 2/12/2019 so that's likely the latest date they published this decision. Their census still shows 41 HK-15 (33 MS and 8 slabbed MS PL).
the density of Brass and Copper is relatively close, so close that any variance in planchet weight could probably account for the slight difference of a specific gravity test, but I'm no scientist. there doesn't appear to be any set standard for the composition of Brass although 95% Copper and 5% Zinc is typical. the thing about Brass is that when it oxidizes the color is similar to Copper so any loss of Gilding on a suspected Copper Gilt medal would have that appearance.
I have enough Brass and Gilt medals that it should be easy enough to look at them and get a sense of color on the Brass to compare with the HK-15 pictured above. I will presume that NGC knows how to test these things to attain an opinion on composition, but I am also willing to assume that this medal was struck in both Brass and Gilt and that NGC got it wrong.
if you look at the medal below, from the SC$ website, the color looks similar to the HK-15 above. Brass will dull as it oxidizes, Gold doesn't oxidize so it stays bright(er).