Log in or Sign up
Coin Talk
Home
Forums
>
Coin Forums
>
Ancient Coins
>
Ancient silver coins - specific gravities
>
Reply to Thread
Message:
<p>[QUOTE="AussieCollector, post: 3284469, member: 81093"]Hi all</p><p><br /></p><p>For interest, I have been conducting specific gravity tests on my silver ancient coins. I primarily do it as another authentication indicator, but I figure I should post the results for the interest of others.</p><p><br /></p><p>The results have been interesting, and mostly as you'd expect. Essentially, the Roman Republic produced very fine silver coins, and the Empire progressively got worse. Greek coins are much the same, with the general rule being the older the Greek coin, the more pure it is.</p><p><br /></p><p>Here is a table of silver specific gravity, with a copper mix. Unfortunately it's not directly translatable, as we cannot assume it's a silver/copper alloy. However, it's the best table I could get my hand on, so it's the comparative I have used.</p><p><br /></p><p>Silver (copper mix)</p><p>.999 = 10.49</p><p>.925 = 10.36</p><p>.900 = 10.31</p><p>.850 = 10.23</p><p>.800 = 10.17</p><p>.750 = 10.08</p><p>.600 = 9.84</p><p>.500 = 9.68</p><p>.400 = 9.53</p><p>.300 = 9.38</p><p>.200 = 9.23</p><p><br /></p><p>The tested coins are included below by date. Comments, questions, musings, and thoughts welcome.</p><p><br /></p><p><b>Thessaly Hemidrachm</b></p><p>480 to 400 B.C</p><p>Obv: Head of Athena, in close-fitting crested helmet</p><p>Rev: Horse's head</p><p>Dry weight: 2.9g</p><p>Suspended weight: 0.28</p><p>Specific gravity: 10.35</p><p><img src="https://img.ma-shops.com/tosunyan/pic/302_29.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>Outcome - this is a fine silver coin, as you would expect of ancient Greek coins, at just a smidgen under 0.925 pure.</p><p><br /></p><p><b>Athens Tetradrachm</b></p><p>350-300 B.C</p><p>Obv. head of Athena to right wearing ivy crested helmet, eye in profile,</p><p>Rev. owl standing to right, head facing, in erect posture, olive twig and crescent behind, to right, **AQE*, all in incuse square</p><p>Dry weight: 17.09</p><p>Suspended weight 1.65</p><p>Specific gravity: 10.38</p><p><img src="https://www.cointalk.com/attachments/upload_2018-11-27_14-18-7-png.850699/" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>Outcome - also pretty darn fine. If we assume a silver/copper mix (which we can't, but I don't have another SG table) the SG would make it just over 0.925 pure.</p><p><br /></p><p><b>Seleucid Tetradrachm</b></p><p>Seleucus I Nicator Tetradrachm, 295 to 291 BC, Susa mint</p><p>Obv: Head of Hercules, in lion skin headdress</p><p>Rev: Zeus seated, with scepter and eagle.</p><p>Dry weight: 16.78</p><p>Suspended weight: 1.61</p><p>Specific gravity: 10.42</p><p>Outcome - This coins is next to bullion silver, at around 0.960 pure silver. It is the most pure ancient silver coin in my collection.</p><p><img src="https://www.cointalk.com/attachments/upload_2018-11-6_9-17-2-png.842543/" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p><b>Thasos Tetradrachm</b></p><p>After 148 BC), silver Tetradrachm, (16.65g)</p><p>Obv: Wreathed head of Dionysus </p><p>Rev: Herakles, standing left, resting on club, lion skin draped over left arm</p><p>Dry weight: 16.65</p><p>Suspended weight: 1.62</p><p>Specific gravity: 10.28 </p><p>[ATTACH=full]868470[/ATTACH]</p><p>Considering this is towards the end of Greek silver coins, this Tetradrachm has a very decent (assumed) silver purity.</p><p><br /></p><p><b>Roman Denarius</b></p><p>Roman Republic, 122 BC</p><p>Obv: Helmeted head of Roma right; X below chin, RVF behind</p><p>Rev: The Dioscuri riding right. Q MINV below, ROMA in exergue</p><p>Dry weight: 3.9</p><p>Suspended weight: .38</p><p>Specific gravity: 10.26</p><p><br /></p><p><img src="https://img.ma-shops.com/tosunyan/pic/795_img_4731.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>This is a high purity silver coin, as would be expected from the Roman Republic.</p><p><br /></p><p><b>Illyrian Drachm</b></p><p>150-50 BC</p><p>Obv: cow standing left with calf</p><p>Rev: double stellate pattern in square</p><p>Dry weight: 2.45</p><p>Suspended weight: .30</p><p>Specific gravity: 8.16</p><p><br /></p><p><img src="https://www.cointalk.com/attachments/upload_2018-11-13_19-51-3-png.845354/" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>The specific gravity of this coin is problematic, so much so that I question the authenticity. There is almost no percentage of silver that would result in a specific gravity like this. However, it is unlikely to be a silver/copper mix, so perhaps it is authentic with a very low silver value. Comments welcome.</p><p><br /></p><p><b>Roman Empire Denarius</b></p><p>Antoninus I Pius, 138-161</p><p>Obv: Laureate head of Antoninus Pius</p><p>Rev: Vesta, draped, standing left, holding simpulum in extended right hand and palladium at shoulder in left</p><p>Dry weight: 3.28</p><p>Suspended weight: .33</p><p>Specific gravity: 9.94</p><p><br /></p><p><img src="https://img.ma-shops.com/linnartz/pic/201555.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>Outcome: this is quite a low specific gravity, particularly for this period of the Roman Empire. A specific gravity of 9.94 would put it at approximately 70% pure. But again, that's assuming a copper mix, which is would almost certainly would not be. Thoughts and comments welcome on this result.</p><p><br /></p><p><b>Roman Empire Denarius</b></p><p>Marcus Aurelius (under Pius), 140 to 144 AD</p><p>Obv:bare head of Marcus Aurelius</p><p>Rev: knife, sprinkler, ewer, lituus and simpulum</p><p>Dry weight: 3.52</p><p>Suspended weight: .35</p><p>Specific gravity: 10.01</p><p>[ATTACH=full]868480[/ATTACH]</p><p>Outcome: this is what I would expect of a Roman Empire Denarius of this period.</p><p><br /></p><p><b>Roman Empire Denarius</b></p><p>196 AD</p><p>Obv: Julia Domna</p><p>Rev: Juno, standing</p><p>Dry weight: 3.2</p><p>Suspended weight: .33</p><p>Specific gravity: 9.45</p><p>[ATTACH=full]868484[/ATTACH]</p><p>Outcome: there was significant debasement during this period, so possibly as expected. However, the SG does seem on the low side. Comments and thoughts welcome.[/QUOTE]</p><p><br /></p>
[QUOTE="AussieCollector, post: 3284469, member: 81093"]Hi all For interest, I have been conducting specific gravity tests on my silver ancient coins. I primarily do it as another authentication indicator, but I figure I should post the results for the interest of others. The results have been interesting, and mostly as you'd expect. Essentially, the Roman Republic produced very fine silver coins, and the Empire progressively got worse. Greek coins are much the same, with the general rule being the older the Greek coin, the more pure it is. Here is a table of silver specific gravity, with a copper mix. Unfortunately it's not directly translatable, as we cannot assume it's a silver/copper alloy. However, it's the best table I could get my hand on, so it's the comparative I have used. Silver (copper mix) .999 = 10.49 .925 = 10.36 .900 = 10.31 .850 = 10.23 .800 = 10.17 .750 = 10.08 .600 = 9.84 .500 = 9.68 .400 = 9.53 .300 = 9.38 .200 = 9.23 The tested coins are included below by date. Comments, questions, musings, and thoughts welcome. [B]Thessaly Hemidrachm[/B] 480 to 400 B.C Obv: Head of Athena, in close-fitting crested helmet Rev: Horse's head Dry weight: 2.9g Suspended weight: 0.28 Specific gravity: 10.35 [IMG]https://img.ma-shops.com/tosunyan/pic/302_29.jpg[/IMG] Outcome - this is a fine silver coin, as you would expect of ancient Greek coins, at just a smidgen under 0.925 pure. [B]Athens Tetradrachm[/B] 350-300 B.C Obv. head of Athena to right wearing ivy crested helmet, eye in profile, Rev. owl standing to right, head facing, in erect posture, olive twig and crescent behind, to right, **AQE*, all in incuse square Dry weight: 17.09 Suspended weight 1.65 Specific gravity: 10.38 [IMG]https://www.cointalk.com/attachments/upload_2018-11-27_14-18-7-png.850699/[/IMG] Outcome - also pretty darn fine. If we assume a silver/copper mix (which we can't, but I don't have another SG table) the SG would make it just over 0.925 pure. [B]Seleucid Tetradrachm[/B] Seleucus I Nicator Tetradrachm, 295 to 291 BC, Susa mint Obv: Head of Hercules, in lion skin headdress Rev: Zeus seated, with scepter and eagle. Dry weight: 16.78 Suspended weight: 1.61 Specific gravity: 10.42 Outcome - This coins is next to bullion silver, at around 0.960 pure silver. It is the most pure ancient silver coin in my collection. [IMG]https://www.cointalk.com/attachments/upload_2018-11-6_9-17-2-png.842543/[/IMG] [B]Thasos Tetradrachm[/B] After 148 BC), silver Tetradrachm, (16.65g) Obv: Wreathed head of Dionysus Rev: Herakles, standing left, resting on club, lion skin draped over left arm Dry weight: 16.65 Suspended weight: 1.62 Specific gravity: 10.28 [ATTACH=full]868470[/ATTACH] Considering this is towards the end of Greek silver coins, this Tetradrachm has a very decent (assumed) silver purity. [B]Roman Denarius[/B] Roman Republic, 122 BC Obv: Helmeted head of Roma right; X below chin, RVF behind Rev: The Dioscuri riding right. Q MINV below, ROMA in exergue Dry weight: 3.9 Suspended weight: .38 Specific gravity: 10.26 [IMG]https://img.ma-shops.com/tosunyan/pic/795_img_4731.jpg[/IMG] This is a high purity silver coin, as would be expected from the Roman Republic. [B]Illyrian Drachm[/B] 150-50 BC Obv: cow standing left with calf Rev: double stellate pattern in square Dry weight: 2.45 Suspended weight: .30 Specific gravity: 8.16 [IMG]https://www.cointalk.com/attachments/upload_2018-11-13_19-51-3-png.845354/[/IMG] The specific gravity of this coin is problematic, so much so that I question the authenticity. There is almost no percentage of silver that would result in a specific gravity like this. However, it is unlikely to be a silver/copper mix, so perhaps it is authentic with a very low silver value. Comments welcome. [B]Roman Empire Denarius[/B] Antoninus I Pius, 138-161 Obv: Laureate head of Antoninus Pius Rev: Vesta, draped, standing left, holding simpulum in extended right hand and palladium at shoulder in left Dry weight: 3.28 Suspended weight: .33 Specific gravity: 9.94 [IMG]https://img.ma-shops.com/linnartz/pic/201555.jpg[/IMG] Outcome: this is quite a low specific gravity, particularly for this period of the Roman Empire. A specific gravity of 9.94 would put it at approximately 70% pure. But again, that's assuming a copper mix, which is would almost certainly would not be. Thoughts and comments welcome on this result. [B]Roman Empire Denarius[/B] Marcus Aurelius (under Pius), 140 to 144 AD Obv:bare head of Marcus Aurelius Rev: knife, sprinkler, ewer, lituus and simpulum Dry weight: 3.52 Suspended weight: .35 Specific gravity: 10.01 [ATTACH=full]868480[/ATTACH] Outcome: this is what I would expect of a Roman Empire Denarius of this period. [B]Roman Empire Denarius[/B] 196 AD Obv: Julia Domna Rev: Juno, standing Dry weight: 3.2 Suspended weight: .33 Specific gravity: 9.45 [ATTACH=full]868484[/ATTACH] Outcome: there was significant debasement during this period, so possibly as expected. However, the SG does seem on the low side. Comments and thoughts welcome.[/QUOTE]
Your name or email address:
Do you already have an account?
No, create an account now.
Yes, my password is:
Forgot your password?
Stay logged in
Coin Talk
Home
Forums
>
Coin Forums
>
Ancient Coins
>
Ancient silver coins - specific gravities
>
Home
Home
Quick Links
Search Forums
Recent Activity
Recent Posts
Forums
Forums
Quick Links
Search Forums
Recent Posts
Competitions
Competitions
Quick Links
Competition Index
Rules, Terms & Conditions
Gallery
Gallery
Quick Links
Search Media
New Media
Showcase
Showcase
Quick Links
Search Items
Most Active Members
New Items
Directory
Directory
Quick Links
Directory Home
New Listings
Members
Members
Quick Links
Notable Members
Current Visitors
Recent Activity
New Profile Posts
Sponsors
Menu
Search
Search titles only
Posted by Member:
Separate names with a comma.
Newer Than:
Search this thread only
Search this forum only
Display results as threads
Useful Searches
Recent Posts
More...
