Question on this 1807 4 Reales...

pcgs69

Does this coin look okay to you ? The area I believe is the mint mark is more of a blob, so wanted to get some more eyes on it. What do you guys think of it? Thanks for any input!

Boosibri

I would be very skeptical. Since it’s raw I would suggest doing a specific gravity test to see if it is even silver.

Abuelo

This is, I think, a Potosi mark. But I woul agree with @Boosibri

ajaan

@Boosibri said:
I would be very skeptical. Since it’s raw I would suggest doing a specific gravity test to see if it is even silver.

How many people here can calculate SP?

Boosibri

Ok> @ajaan said:

@Boosibri said:
I would be very skeptical. Since it’s raw I would suggest doing a specific gravity test to see if it is even silver.

How many people here can calculate SP?

If you have a scale, some string, a container and YouTube I’m sure anyone here can figure it out.

pcgs69

I gave specific gravity a test. I'm sure it's not 100% flawless but this is what I got:
Weight 13.16 grams
gravity of 1.3
SG of 10.12

Boosibri

That’s about right for 0.900 silver

jayPem

Potosi mint marks came out blobular sometimes...😜

realeswatcher

SG is actually a bit low for ~ .900 silver, but the piece presents as genuine (look at other 1807 Potosi examples and you'll see that blobbish mintmark isn't out of the ordinary). SG could be some process error, plus I dont really trust Potosi alloying to be perfect around this time.

Perhaps relatedly, though this is really just my casual observation, some of the Potosi 4R around this time seem to... well, not have stood up to circulation well. That is, some seem to just be rather scuzzy... like the metal wasn't super-resistant to environmental exposure. Again, that's anecdotal.

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PS - There actually IS a pretty convincing circulated-looking Chinese fake of the scarce date 1809 Charles IIII Potosi 4R to be aware of.

jgenn

I hate to sound like a broken record but is the edge design correct and does it look like it was impressed on a parallel edging mill?

pcgs69

@jgenn said:
I hate to sound like a broken record but is the edge design correct and does it look like it was impressed on a parallel edging mill?

Is this image ok? I can try to get more if you’d like.

jgenn

So we are looking for evidence that the edge was made by a parallel edging mill. Here's a link to a post from Bob Gurney about how such a device leaves telltale overlaps of the edge design.