| Author |
 Replies: 16 / Views: 4,615 |
|
New Member
Australia
19 Posts |
I have come across this 20 cent coin, and have seen some more like it also, I do have a $2 coin with the same sort of markings, so Iam assuming error, to me they look like Triangle shaped indentations, and they are definatly not Raised....Could someone please explain to me what they could possibly be, thanks so much  
|
|
|
|
Pillar of the Community
Australia
2180 Posts |
I think it is the reeded edge of another coin hitting the Queen's face and leaving an imprint.
|
|
Pillar of the Community
Australia
4411 Posts |
It is definitely the reeded edge indenting the coin face and therefore PMD. Get two coins and hammer and you will be able to replicate it exactly. Edited by enworb
11/20/2012 12:27 am
|
|
Formerly nancyc
Australia
5385 Posts |
 Impact by other coins, very common.  life is a mystery to be lived not a problem to be solved
|
|
Bedrock of the Community
Australia
21786 Posts |
Otherwise known as 'bag marks'. This is a rather obvious example of a very common form of damage sustained by coins when they leave the press, and drop onto each other in a heap.
The coins are gathered in bulk and bagged (not rolled). Hence the reason for the term 'bag marks'.
|
|
Valued Member
Australia
369 Posts |
I have yet to be convinced that the reeded edge of another coin causes this.
The reeded edge is straight so why is the result triangular?
The reeded edge is closely packed so why is the result of the triangular shapes further apart? The reeded edge around the coin is circular so why is the result a straight line if it is just falling into a bucket?
One thing is sure though. It is damage.
|
|
Bedrock of the Community
United States
12437 Posts |
If you are not convinced that a hit from another coin is the cause, then you should reproduce the damage yourself. Place one coin on a flat surface, take another coin and place it at an angle with reeding down, whack the second coin with a hammer or other hard object and then you will see the hallmark linear scallop shape of a reeding mark.
|
|
Valued Member
Australia
369 Posts |
Sorry,I'm still not convinced.
|
|
Valued Member
Australia
428 Posts |
in the mint coins fall into a bin and hit other coins already in the bid , but I dont believe they hit hard enough to make a mark as bad as that , remember coins are made from metals that make them so hard it has to be hit very hard to leave an imprint such as the one shown above. my call PMD for sure.. ,, kel ,, |
|
Valued Member
Australia
369 Posts |
That's exactly what I think. Unless someone knows for sure at what force the coin is ejected. I am half convinced though. I can get a similar result with a hammer but why does it always have to be at an angle? Doesn't any coin hit another straight on and leave an impression of the whole reeding?
|
|
Pillar of the Community
Australia
1005 Posts |
If the reeding was straight on, the force would be spread over a larger area, so much more force would be required to leave marks.
|
|
Pillar of the Community
Australia
4411 Posts |
Quote:
If the reeding was straight on, the force would be spread over a larger area, so much more force would be required to leave marks. I would stake my entire collection on this type of damage being made by another coins reeded edge. This type of danage does not neccessarily happen at the mint when they are ejected from a hopper. Imagine some coins in an armaguard bag. They get thrown about quite a bit. The weight of all the other coins on top could exert quite a bit of force, enough to create this damage. |
|
Bedrock of the Community
Australia
21786 Posts |
airgem may have a point worth proving, and that can be done.
I don't have my vernier calipers with me just now.
Measure the millings on the rim of the coin, and compare that to those on the obverse of the coin. The pictures on the screen can be used, but they would need to be scaled.
|
|
Valued Member
Australia
369 Posts |
I have managed to convince myself and agree totally that the reeding of another coin causes this. Placing one coin on top of another with this impression it lines up exactly. I'm now going to get my eyes tested!!
|
|
Pillar of the Community
Australia
750 Posts |
Quote:
I'm now going to get my eyes tested!!
I'd reckon your eyes are pretty good if you can see the indent and milling line up ..... far better than mine ..... I'd have several magnifying glasses out with a camera too then probably still couldn't see it!  I've noticed that this marking is particularly common on 20c pieces (almost makes you think it's claw related sometimes)  . Must be relevant to the size of the milling, coin size ratio etc as they obviously position themselves in an appropriate position in bags for this to happen when bags are dropped ...... or thrown (heaven forbid!!) |
|
Valued Member
Australia
369 Posts |
Well I did cheat and wore glasses and used a loupe. Without them i'd have to take up gardening or something. |
| |
Replies: 16 / Views: 4,615 |
Posted 11/20/2012 12:02 am
