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 Replies: 15 / Views: 3,232 |
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New Member
United States
7 Posts |
The Perth Mint only lists the Maximum dimensions for the 2021 1oz Gold Kangaroo. I contacted Perth, but they will not provide anything more. Does anyone have an authentic coin they can confirm measurements? Measured: Weight 1.0001 Troy Oz Thickness: 2.36mm Diameter: 32.01mm |
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Moderator
 United States
56855 Posts |
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New Member
 United States
7 Posts |
Edited by gold1
07/02/2021 10:31 am
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Moderator
United States
56855 Posts |
Please post a full coin photo front and back of your coin. John1  |
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New Member
United States
7 Posts |
I have a microscope camera, so I can zoom up on anything suspicious   Edited by gold1
07/02/2021 6:06 pm
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Moderator
United States
187446 Posts |
 to the Community! |
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CCF Master Historian of USA Commemoratives
United States
12250 Posts |
The Perth Mint doesn't make multiple sizes of its one-ounce gold Kangaroo coin; all of the one-ounce Kangaroo coins it produces have the same specifications. The specifications for each have very tight tolerances (gold is expensive!) and the "maximum" specifications you have read about are related to these tolerances. Such variations are measured in the hundredths place, and would not result in the 0.59 mm difference in diameter or 0.59 gram weight difference you have listed. If the measurements you've listed for your coin are accurate, I would take the coin to a local coin store and find out if they can verify whether it is a real Perth Mint coin vs. a counterfeit. It is physically impossible for a coin to be simultaneously smaller in diameter and thinner and still have one ounce of pure gold. Good counterfeits can match the correct weight by using various alloys that are not pure gold (as the Perth Kangaroo coin should be). Good luck! Let us know what you find! Collecting history one coin or medal at a time! (c) commems. All rights reserved.
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New Member
United States
7 Posts |
It does pass the ping test It is the right weight It is not Magnetic. It appears stamped, not poured For the volume to be smaller, the density would have to be greater. There are no inexpensive metals with a higher density that would make sense. I contacted JM Bullion, they simply blew me off and said its within specifications. The dimension being off is haunting me. I doubled checked the measurements. With calipers set to 32.6mm, the coin had plenty of play. It simply does not have that diameter Edited by gold1
07/05/2021 3:46 pm
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Pillar of the Community
Canada
3733 Posts |
where did you buy it from.?
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New Member
United States
7 Posts |
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Pillar of the Community
United States
1005 Posts |
My best guess here is the caliper measurement is off - either you're not measuring the coin the same way they do or your calipers aren't calibrated properly
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New Member
United States
7 Posts |
When I measure a US coin, it measures correctly
My next step is to try to get an accurate specific gravity measurement
Edited by gold1
07/06/2021 6:06 pm
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Valued Member
Australia
112 Posts |
I don't know any of the nitty gritty details but it's a very pretty coin.
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New Member
United States
7 Posts |
Back to the specific gravity measurement:
Okay, got the 0.001g accuracy scale.
Using ~4 degree distilled water, and accounting for the thread weight, the specific gravity is: 19.2706.
SG of gold is 19.300. Error = 0.15%
The gold is 0.9999 pure...
So the SG checks out. I still can't explain the dimensions being off
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Pillar of the Community
Australia
2180 Posts |
Maybe the Perth Mint information is just wrong? Is there another coin that they made with those dimensions? Possibly they accidentally used dimensions from an existing ad/box. |
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Pillar of the Community
Australia
1333 Posts |
hmmm well Australia did have a redesign of Effigy (observer-side) but I would have thought Perth Mint wouldn't want to change size of dies or make changes to their bullion coins, I mean unless they couldn't get capsules of a particular size then it make sense to make the coin the size of the capsules? |
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Replies: 15 / Views: 3,232 |
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Posted 07/02/2021 10:29 am
