Micro-Numismatic Quiz #13

Insider2

Sorry, no prizes

I am going to be posting micrographs of anything that can be found on coins. Some will be easy and some will not. The correct answer is whatever I say it is but feel free to disagree (giving your reason) so all of us can discuss it. Images will be posted in this thread at my discretion - several each week. I will usually post the answers late the next day after the quiz was posted.

In order to make this FUN for beginners. I'll ask the "experts" to PLEASE not guess what any of the images are until the next day. Otherwise, folks like (fill in the blank) will get all of them immediately - That's NO FUN. If no correct answer is given by the next day, the "experts" should PLEASE respond. The answer for each image will usually be posted in the afternoon when I add another image.

The Rules:

1.Anyone can guess. That's because even an incorrect guess can open further discussion as to why it is incorrect.
2.The BEST guess is in two parts:

A. What characteristic the image shows.
B. What did you see in the image that led to your guess.

The Question: What micro-characteristic do you see on this coin's surface? What does it usually signify?

The Image:

JBK

Little bumps - often seen on cast counterfeits.

Hemispherical

A micro maze.

Raised dots along the relief. Indicates that the coin was cast. I think.

Insider2

@Hemispherical said:
A micro maze.

Raised dots along the relief. Indicates that the coin was cast. I think.

@JBK said:
Little bumps - often seen on cast counterfeits.

LOL! Are you sure?

Akbeez

The beads are created by trapped bubbles of air -- presumably through a casting process. Though I can't quite visualize the entire process...

MikeInFL

I have no idea, but I thought that casting bubbles were more uniform as opposed to just along the devices and they were incuse not excuse....but what do I know?

Fascinating thread.

Namvet69

So I was gonna say gas bubbles but......JBK caught me off guard with the old fakeroo! Peace Roy

AUandAG

coin was struck but the die that was used was cast.

bob

Hemispherical

@AUandAG said:
coin was struck but the die that was used was cast.

bob

Would that be a counter cast die?

Aspie_Rocco

Pitted or rusted die

Hemispherical

Took a break and zoomed out.

Additional observation, the bumps seem to occur at approximate equal distance apart but not necessary of the same diameter. So this leads me to guess that it was man-made and was part of the design (either intentional or non-intentional).

Which leads me to...
...nowhere. It’s like someone decided to stick a toothpick along the edges of the relief. Toothpick is tapered so a slight prick are the small bumps and the deeper the toothpick goes in the larger the bump.

Akbeez

Hmmm. I know of no US coin with non-uniform decorative devices such as this Hemi -- as they are not uniform in either size or distance. Still thinking it's counterfeit by means posted above.

Hemispherical

I agree @Akbeez. Me thinks that Insider2 is trying to throw me off. lol

PerryHall

This is a tough one. Either trapped air bubbles in a cast die used to strike a counterfeit coin or rust pits in a die resulting in raised bumps on the coin struck with this die. These quizzes are giving me a real education and a real headache.

Insider2

The coin is a cast counterfeit of a British Trade dollar made out of copper. Perhaps the next step was to plate it with silver. The "lumps" are smooth and basically rounded. They are raised on the coin. They are caused by bubbles. Now someone tell us if the bubbles were trapped in the casting mold or if they were trapped in the metal that was injected into the mold.

PerryHall

The bubbles have to be trapped in the mold to be a raised rounded bumps on the coin. If the bubbles were trapped in the metal they would appear to be rounded pits in the surface of the coin. These quizzes are a great series of threads. Keep them coming.

JBK

Agree with PH. The raised bumps are metal, not air, so they represent voids in the mold created when the mold was made.

Hemispherical

@Insider2 said:
...Now someone tell us if the bubbles were trapped in the casting mold or if they were trapped in the metal that was injected into the mold.

More thank likely reading way too much into this.

Injection and pour are two different methods.

Pour can leave bubbles because of trapped air/gas/fumes in the mold, thus the reason to tamp the mold during and after the pour.

Injection, if under pressure, usually does not have the the trapped air/gas/fumes so any that form is in the metal.

I reviewed what I typed and I AM reading too much into this. Lol

Edit to add. What do I know? I don’t. Getting some edumacation, I am.

Insider2

@Hemispherical said:

@Insider2 said:
...Now someone tell us if the bubbles were trapped in the casting mold or if they were trapped in the metal that was injected into the mold.

More thank likely reading way too much into this.

Injection and pour are two different methods.

Pour can leave bubbles because of trapped air/gas/fumes in the mold, thus the reason to tamp the mold during and after the pour.

Injection, if under pressure, usually does not have the the trapped air/gas/fumes so any that form is in the metal.

I reviewed what I typed and I AM reading too much into this. Lol

Edit to add. What do I know? I don’t. Getting some edumacation, I am.

This is correct. No matter how the mold is charged (even vacuum) there is a chance for a bubble to occur.>

@PerryHall said:

The bubbles have to be trapped in the mold to be a raised rounded bumps on the coin. If the bubbles were trapped in the metal they would appear to be rounded pits in the surface of the coin. These quizzes are a great series of threads. Keep them coming.

Congratulations! You have OFFICIALLY disqualified yourself from answering future quizzes until the "experts" start posting on day two. I hope that is OK with you. That way others can have a chance to think out the answers.

Hemispherical

@Insider2 said:
@PerryHall said:

The bubbles have to be trapped in the mold to be a raised rounded bumps on the coin. If the bubbles were trapped in the metal they would appear to be rounded pits in the surface of the coin. These quizzes are a great series of threads. Keep them coming.

Congratulations! You have OFFICIALLY disqualified yourself from answering future quizzes until the "experts" start posting on day two. I hope that is OK with you. That way others can have a chance to think out the answers.

Is that for pre- or post bam PH? LOL

kaz

see "Numismatic Forgery" by Larson, pp.47-48

Hemispherical

@kaz said:
see "Numismatic Forgery" by Larson, pp.47-48

Thank you @kaz. I will be looking into it.

MikeInFL

So the die was a casting with bubbles that were then transferred to the struck copy of this British trade dollar?

Insider2

@MikeInFL said:
So the die was a casting with bubbles that were then transferred to the struck copy of this British trade dollar?

No die was involved. There was a bubble on the genuine coin used to make the mold. The bubble kept the mold material from reaching the coin's surface. That left a round depression in the mold. When the cast was made, the metal flowed into the design and into the bubble hole. That left a raised, round, bubble shape on the counterfeit.