1790 Carolusiiii With Bust Of Carolus 4 - Fake?

I would also appreciate comments from Mr Swamperbob.

Please allow me to clarify, the whole "date" area looks altered (wrong) to me.

I know there is no Carolus 4 bust for year 1789 or year 1790.
But the ring or the sound of the coin when it hit the hard surface / table is the same as my other genuine old 8 reales of that decade/period.
I am definitely sure that this is NOT a modern fake.
Subjecting the coin to X-ray scan (not yet done to this coin) will prove that it is not made of NEW silver, not recently forged. Since I am not able to measure the specific gravity accurately (to do this, I need to specially import a digital spring scale from USA for small mass item), so I tried the X-ray machine which is easily available to me. From X-ray photos, I can easily distinguish old dense silver (old silver which has undergone some crystalization) from newly casted silver.

We will wait for swamperbob's comments or suggestions

Bamboo Nice coin.

Weight is about correct for wear. SG average is correct so likely the alloy is correct.

Die style looks real - designs are essentially correct.

BUT - it does not exist as a date. So what is it?

Two possibilities exist - (1) Altered date original or (2) A counterfeit.

I agree with the writer who said the date looks funny. The area near the date is clearly weakly struck - and the area directly opposite on the reverse is also weakly struck - so the planchet was likely thinner at this point resulting in the weakness on both sides. However, the 0 appears TOO strong when compared to the other side and it could be an engraved digit.

But I also agree with the last comment that the edge design looks very much like a Boston edge. That style applies to any one of the late 1800s bullion forgeries made to ship to China. The circles do looks squarish. There are 1790 coins of the Bullion Class made with the wrong portrait. The die break that you enlarged is also fairly similar to the "soft breaks" that are regularly seen on forgeries of this type.

I believe the coin is a contemporary forgery of the type made in the 1890s which MAY have been altered. That would make it a really interesting DOUBLE FORGERY.

But in no case to I believe the coin is a real 1790 with the Charles IIII portrait.

Bamboo Yes in my opinion you have it correct as far as #1 goes. The coin certainly appears to be of the general "Boston" style - a bullion forgery made for use in China. These were produced in many locations one of which was Boston. I refer to the group collectively as "Boston" style because that is where I first learned about their existence. Since that time, I have documented many other areas that produced similar coins.

The open issue is was the coin originally dated 1790 of did someone at a later date alter or add the final digit. This will require a good binocular microscope and some familiarity with looking at faked coins. Usually the letter is added by cutting away metal form the flat field and leaving the desired letter or number higher than the depression. The second most common method involves adding the letter or number to the surface. This can be done with glue (but an acetone bath should dissolve most glues) or a small lump of metal can be soldered onto the surface and then cut to the desired shape. All of the methods leave clues so look for seam lines, signs of tool marks, abrasion and polishing. In the case of soldering loot for heat damage or color changes.

Swamperbob & All,
1) I have examined the 1790 under a microscope (under high magnification & higher magnification) - observations of 3 persons :-
a) Surfaces surrounding the numbers are the SAME as the other parts of coin
b) No tool marks, no burnt mark, no colour change, no fine lines due to polishing
c) The "borders" of the numbers are Sharp, Clear & Fine not Fuzzy - no rough cuts / lines

2) The coin has been examined by a coin expert ( specifically to look for alteration in the numbers). His comments are 'the numbers look sharp when viewed with a loupe' & 'no alteration done to the numbers'.
So it looks like there is only "SINGLE FORGERY" ?

Bamboo It is most likely a forgery of the "Boston" type in my opinion.

The Boston types include many examples of date - mint - king combinations that never existed.

Bamboo Typically someone like me would probably pay in the $50 to $100 range for a coin such as this. So it is definitely NOT a melt item. If you ever want to get rid of it let me know it would be a good addition for the upcoming publication on Portrait counterfeits as long as the date was NOT engraved.