Electrum Pieces!!!

[TheAuldGrump]

Poking around a bit...

Mild steel seems to have a Vickers scale hardness of about 140. Hardened steel on that scale runs around 900. Various platinum alloys run from something like 130 to 350.

So, these days surely you can use a hardened steel press. If in game the folks only have mild steel, they might have issues. Or, you could just cast the coins, getting around the whole press problem. You don't generally want to cast small-value coins, but for high value ones, it might make sense.

However, in a medieval setting good hard steels for coin presses are not available. Though to be completely honest neither was platinum... Earliest reference is 1557, when it was considered a waste metal... And platinum has a Vickers hardness of 549, not 140... harder than most steels even today.

Lost wax casting would be possible, but having to make a new master for each coin rather misses the point of standardized currency.

For my own homebrew game coins are either copper (or, more rarely, bronze) or silver. Over a certain value coins are assayed by weight rather than number. I do not use a single standardized weight for coins, so there are a number of copper and silver coins, with 1, 3, and 5 CP coins being common, the most common silver piece is a single rectangular coin called a 'ship', which is strip minted in groups of 12 to form a longer coin called a fleet, a full fleet being worth 12 SP, but is most often found cut short. I even drew up a picture of the rotary press used for minting a fleet. (Most coin presses are of dwarfen or gnomish manufacture.) A fleet is a convenient size to be worn as a bracelet. Counterfieting, clipping, and drilling are all common, though illegal. *EDIT* For convenience lengths of 4 or 8 are most common.

The Auld Grump

 

[Umbran]

However, in a medieval setting good hard steels for coin presses are not available. Though to be completely honest neither was platinum... Earliest reference is 1557, when it was considered a waste metal... And platinum has a Vickers hardness of 549, not 140... harder than most steels even today.

Having gotten home, I now have access to my CRC Handbook of Chemistry and Physics. It is a 1988 Edition, so perhaps some of the historical stuff is out of date, but it claims platinum was known to pre-Columbian folk in Central and South America.

And it strongly disagrees with your hardness number. It has platinum with a mean Vickers hardness of 126. Certainly harder than silver, gold, and electrum, which are down at 53 and 51 and 40, respectively. Copper already has a hardness of 134.

Just to be sure, looking at Mohs hardness too - Platinum has a 4.3. Iron 4 to 5. Steel 5 to 8.5.

 

[Stormrunner]

...Lost wax casting would be possible, but having to make a new master for each coin rather misses the point of standardized currency.

Nah, you just take your standardized coin press, and stamp out a bunch of identical wax masters. Hook 'em together with sprues, cast the lot, and cut 'em apart afterwards. Just like casting minis.

 

[Loincloth of Armour]

What the heck is Adamantine anyways? An alloy? Refined Adamantite by Azer in a volcano?

From SRD:

Adamantine
This ultrahard metal adds to the quality of a weapon or suit of armor. Weapons fashioned from adamantine have a natural ability to bypass hardness when sundering weapons or attacking objects, ignoring hardness less than 20. Armor made from adamantine grants its wearer damage reduction of 1/- if it’s light armor, 2/- if it’s medium armor, and 3/- if it’s heavy armor. Adamantine is so costly that weapons and armor made from it are always of masterwork quality; the masterwork cost is included in the prices given below. Thus, adamantine weapons and ammunition have a +1 enhancement bonus on attack rolls, and the armor check penalty of adamantine armor is lessened by 1 compared to ordinary armor of its type. Items without metal parts cannot be made from adamantine. An arrow could be made of adamantine, but a quarterstaff could not.

Only weapons, armor, and shields normally made of metal can be fashioned from adamantine. Weapons, armor and shields normally made of steel that are made of adamantine have one-third more hit points than normal. Adamantine has 40 hit points per inch of thickness and hardness 20.

[/end quote from SRD]

So adamantine = adamantite, but changed to prevent any copyright infringement. Much like mithral = mithril.

 

[lukelightning]

Electrum? Damn near killed him!

 

[TheAuldGrump]

Having gotten home, I now have access to my CRC Handbook of Chemistry and Physics. It is a 1988 Edition, so perhaps some of the historical stuff is out of date, but it claims platinum was known to pre-Columbian folk in Central and South America.

And it strongly disagrees with your hardness number. It has platinum with a mean Vickers hardness of 126. Certainly harder than silver, gold, and electrum, which are down at 53 and 51 and 40, respectively. Copper already has a hardness of 134.

Just to be sure, looking at Mohs hardness too - Platinum has a 4.3. Iron 4 to 5. Steel 5 to 8.5.

Jewllers platinum I believe does have a hardness of 126, but is an alloy (iridium?) . Let me check online... here and Wikipedia (which I do not entirely trust) here and an environmental chemistry site for good measure - 549 on all of them... either the same mistake is being made a lot, or something is off with your numbers...

The Auld Grump
*EDIT* Googled under Chemistry Platinum Vickers and Hardness, if you want to repeat the process, then picked randomly among the resulting sites (there were a lot of them). Wikipedia was searched on its own, simply because I have it bookmarked (convenient, yes, trustworthy...?).

*EDIT 2* Doing the same with Iron seems to show any number between the low 400s and the low 600s... with a prevalent answer of 608, higher than platinum... but a lot more varience it seems, trying to do the same with steel would be an exercise in futility I think.