File:Kan'ei Tsūhō (寛永通寳) Maruichi (cast version) - Dr. Luke Roberts 01.png

A few coins are easily identifiable because special markings were put on the rims at the mint either by casting or by hammering with a die. These range from the moderately uncommon to the rare. The rim markings in copper alloy coins are easy to see while the ones in iron coins usually are difficult to see at first. I do not own many of these but below are a couple of examples. One has a "circle ten" (marujuu) mark and the other a "circle one" (maruichi) mark. Ones with the three parallel lines of the "river" character are also not too uncommon. The placement of the marking is usually at 1:30 if single, or at both 10:30 and 1:30 in a pair as in the examples below. Markings elsewhere on the rim exist but are more rare.   Marujuu (cast version) Edo Juumantsubo (1736) 23mm wide x 1mm thick detail of left,this coin has only one rim mark at 1:30 on rim Maruichi (cast version) Nagasaki Ichinose (1740) "large shell Hou" ííçûä€àÍëÂäLõê 23mm wide x 1mm thick detail of left. This coin has two rimmarks at 10:30 and 1:30 on the rim. The rim mark on this one was cast into the mother coin.

There is also a die hammered version of this rim mark (the circulating coin itself was cast as normal) which was produced in 1739. The "marujuu" is half again as large and usually the whole image cannot be seen as it is larger than the rim itself. See below   There is also a die hammered version of this rim mark, below. the mark is the same size but the "ichi" (horizontal bar) is often tipped in angle to the left or right, whereas the cast ones are always horizontal. The die hammering was done on the mother coin.

This coin to the left is a Marujuu die version, meaning that the juu on the rim was made by hammering with a die into the rim. As a result the orientation is often tilted.

This is like the coin above with two marks at 10:30 and 1:30 o'clock, but note that the maruichi is almost vertical. it is an example of the die hammered version. It also has a casting error, leaving a hole. This coin belongs to Bill Dunkle who kindly let me use the image.