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Message: <blockquote data-quote="aramis erak" data-source="post: 6593719" data-attributes="member: 6779310">Quibble over the details...Platinum, pure 21.4 g/ccGold, 24k, 19.6 g/ccsilver, 0.999fine,  10.49 g/ccCopper 8.9 g/cctin 7.2 g/cczinc 7.31 g/ccElectrum is a problem - it has 2 common formulations which are gold & silver alloy... but it's defined as 20-80% gold and 20-80% silver, with the balance in base metals (copper, tin, zinc, antimony)<ul> <li data-xf-list-type="ul">Lycean: 45-60% gold 35-55% silver, 0-5% base metals </li> <li data-xf-list-type="ul">Anatolian: 70-90% gold, 9-30% silver, trace base metals</li> <li data-xf-list-type="ul">German: 60% copper, 20% tin, 20% zinc</li> </ul>Coin gold is typically 14k, (58%,) with the balance being copper, and a specific gravity of about 15.1g/cc. Lets call this our base worth for gold coin... which is a good thing, since pure gold (24k) is worth about 12 to 20x silver... and this gives about 1 15.5:1 ratio to the silver coin, and thus pure gold worth about 1.55x coin goldCoin Silver is usually 90% silver, the balance being largely copper; pure silver doesn't wear well enough. Some medieval silver coinage was as low as 50%, usually mixed with tin, zinc and copper.  90% is about 10.4 g/cc... 50% is about 9.7 g/ccCoin Copper, is almost always alloyed with tin and zinc, and sometimes with gold or silver. But copper's inherent value is about 1/70th that of silver in the medieval era. So, to plus it up, say, 5% silver... if we go with 90 copper, 7.5% silver, 2.5% zinc, we get about the right value, about the right hardness, and about the right brightness, and a historic coin composition. We also get about 8.98 g/ccNote that the platinum coin, given the generally medieval tech, is anchronistic, and would require magic to work. (developing the ore isn't the problem, despite being essentially victorian; actually working it, however...) So, assuming nearly pure is fine. Setting the value to 10x gold (rather than the current 0.9x) is thus easily justified.And, for electrum, let's go really debased... 27% gold (worth 0.419 gp), 70% silver (worth 0.07 gp) 3% copper. It's about 12.8 g/cc and worth just shy of half a gpSo, recapping more realistic coin-densities, and 9.07g per coin. 3 figure accuracy<table style='width: 100%'><tr><td>Platinum coin (magically pure)</td><td> 21.4 g/cc </td><td>0.424 cc</td><td>23.2x1mm</td><td>19.0x1.5</td><td>16.4x2mm</td></tr><tr><td>Gold Coin Alloy 14k</td><td>15.1 g/cc </td><td>0.601 cc</td><td>27.7x1mm</td><td>22.6x1.5mm</td><td>19.6x2mm</td></tr><tr><td>Low Gold Electrum 0.27/0.70</td><td>12.8 g/cc</td><td>0.709 cc</td><td>30x1mm</td><td>24.5x1.5mm</td><td>21.2x2mm</td></tr><tr><td>Coin Silver Alloy .900 fine</td><td>9.7g/cc</td><td>0.935 cc</td><td>34.5x1mm</td><td>28.2x1.5mm</td><td>24.4x2mm</td></tr><tr><td>coin copper alloy (5% silver)</td><td>8.98 g/cc</td><td>1.01</td><td>35.9x1mm</td><td>29.3x1.5mm</td><td>25.4x2mm</td></tr></table>1.01 cc[/td]</blockquote>

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