Thrace - Byzantium - Bull on dolphin type - denominations

[Myrmidon]

I recently acquired a Byzantium coin of the following type:

Obv.: Bull on dolphin,     above
Rev.: Mill sail incuse (dotted)

My coin weighs 2,35g and has a diameter of 13mm.

While researching to get more information about this coin, I noticed that different denominations are used for this type/weight. Can anyone offer some insights?

1) Fifth stater (assuming they mean 1/5th) of the Persian standard. If I'm not mistaken, a Persian stater is a daric, 8.1g and later 8.4g
1/5 x 8.1 = 1.62 g   
1/5 x 8.4 = 1.68 g 

http://www.s391106508.websitehome.co.uk/PHP/SNG_PHP/04_03_Reply.php?Series=SNGuk&AccessionNo=0901_0036
http://www.s391106508.websitehome.co.uk/PHP/SNG_PHP/04_03_Reply.php?Series=SNGuk&AccessionNo=0901_0037

2) Half siglos. I assume a Persian siglos of 5.4g or 5.6g
1/2 x 5.4 = 2.70 g 
1/2 x 5.6 = 2.80 g 

http://www.s391106508.websitehome.co.uk/PHP/SNG_PHP/04_03_Reply.php?Series=SNGuk&AccessionNo=0300_1175
http://www.s391106508.websitehome.co.uk/PHP/SNG_PHP/04_03_Reply.php?Series=SNGuk&AccessionNo=1100_0002

3) Hemidrachm, but which standard?
2 x 2.46g (coin in url) = 4.92g

http://www.s391106508.websitehome.co.uk/PHP/SNG_PHP/04_03_Reply.php?Series=SNGuk&AccessionNo=0700_0773

4) Tetrobol, but which standard?
6/4 x 2.33 g = 3.5 g

https://www.wildwinds.com/coins/greece/thrace/byzantium/sg1582.txt

[Altamura]

During the fifth and fourth century BC Byzantion used two different weight standards.

The Persian standard had an average weight about 5.4 g for the drachm, the Rhodian standard about 3.7 g.

All this and much more you can read (in German) in Edith Schönert-Geiß, "Die Münzprägung von Byzantion", Berlin 1970, which is available online here:
https://edoc.bbaw.de/frontdoor/index/index/docId/2996
https://edoc.bbaw.de/frontdoor/index/index/docId/2997

Regards

Altamura

[Myrmidon]

Thank you for the information! A tetrobol related to the Rhodian standard makes sense for a weight of 3,35g - 3,45g.
Don't really understand the fifth stater or half siglos though.

[Myrmidon]

I found an answer to my question, thanks to the documents Altamura suggested to check.
I'm not sure why a hemidrachm is not half the weight of a drachm, but a weight of 2,4g is considered to be a hemidrachm (and I guess half siglos) of the Persian standard.

[Altamura]

... I'm not sure why a hemidrachm is not half the weight of a drachm ...

Fractions have mostly a bit less than the weight they should have by calculating it down from the stater. This was part of the profit of the authority producing the coins  .

Regards

Altamura

[Myrmidon]

Thanks for the info!    

[Meepzorp]

Hi Myr,

I am a moderator of the Greek section of Forum. I modified a few of your posts here in this thread. You are not supposed to quote the post directly above your post. Owner Joe doesn't like it when you do that. The only exception is when you are quoting a small portion of the post above.

Also, I deleted your photo because the image wasn't there. Obviously, there was some sort of technical problem with your photo.

Meepzorp

[Altamura]

... Also, I deleted your photo because the image wasn't there. Obviously, there was some sort of technical problem with your photo. ...

Which photo are you talking about? Haven't there been two, one of the coin and a snippet of the book?
Yesterday I didn't have any problems to see them both.

Regards

Altamura

[Meepzorp]

Hi Alta,

I am referring to the photo that was in Myr's post ending in "...Persian standard".

Are you stating that you were able to see that photo? That is strange. I couldn't see it. On my end, it was a dead link/photo. There was no photo/image there. All I could see was the icon for a dead link/photo (in other words, the icon for a photo/link that doesn't exist). From that point down, my screen was blank. It was all empty space on my end.

It is the same icon I see on my computer when one of the photos in my website is mis-numbered or contains a typo.

Perhaps Myr can re-post it and we can determine if other Forum members can see it?

Meepzorp

[Myrmidon]

I hope this works now.

[Meepzorp]

Hi Myr,

Now I can see it. What did you do differently?

Meepzorp

[Myrmidon]

Previously I used a link to google photos