Guernsey 1 double 1830
This little copper coin, mintage 1,648,640, is fairly easy to find. It is not expensive (about $5-10), but most samples offered in this price range are in rather poor condition. After purchasing several specimens I have realized that some of them are from different dies (which is not unexpected given high mintage number). My analysis is, as far as I know, is the first one, so please take it with a great deal of scepticism! Hope it will be used as a starting point for future studies by collectors who have access to better and more versatile material.
A 'dot before date' variety is included here as Reverse 5. This one is rare and can be expensive in high grade. Another sample image: https://www.numisbids.com/n.php?p=lot&sid=714&lot=50.
Obverse side is one with a Guernsey shield, reverse side is one with a date.
Obverse die variations are surprisingly hard to detect. I had to compare images by overlaying them in graphics editor, otherwise they are indistinguishable from each other. This needs more work and more samples!
|Obverse A. Seems to be most common.|
|Obverse B. This one is from my 'dot before date' sample.|
There are several points of identification. Examine the relative position of letters L and E, distance between L and E, outline of upper digit 1. All differences are small and have to be checked at high magnification.
|Reverse 1. Base of E is strictly level with base of L. Outline of upper digit 1 is regular. Top of the lower 1 is slightly sloping.|
|Reverse 2. Base of E is noticeably higher than base of L. Outline of upper digit 1 is irregular below top serif. Top of the lower 1 is flat, no slope at all.|
|Reverse 3. There's a miniscule dot before date. The dot is very, very small; open high-resolution photo to see it. It is not a defect. I have seen another coin on eBay which also has this dot. Base of E is level with base of L. E is closer to L than in reverse 1. Outline of upper digit 1 is regular. Top of the lower 1 is slightly sloping.|
|Reverse 4. Base of E is a little higher than base of L. L is slightly further from E than in reverse 2. Zero is clearly higher than rest of date figures. Upper digit 1 is poorly engraved under top serif. Top of the lower 1 is flat, no slope at all.|
|Reverse 5. Large dot before date (E1A in Exley catalogue). The dot is large and aligned nearly with bottom of date. Base of E is almost level with base of L. Outline of upper digit 1 is regular. Top of the lower 1 is slightly sloping.|
|Reverse 6. Base of E is almost level with base of L (slightly higher). Outline of upper digit 1 is regular. Top of the lower 1 is slightly sloping. This one is similar to reverse 1, but word DOUBLE is longer in reverse 1.|
Coins from my collection
I have ten samples and hope to acquire more in the future. Obverse classification is quite dubious.