Toning on a "new" Sintered Planchet coin....???
AskRaq
Posts: 2,303
Okay... in trying to figure out the difference between sintered & burnished/unburnished... I came across these AMAZING & UNBELIEVABLE twin coins:
Fresh from OBW - Sintered & peac.ock TONED??
Someone, tell me please.... is this from baking on a cookie sheet, or is it chemical... or WHAT?!?!
(Sorry for the period above, in the middle of the bird word... but it wouldn't let me post it with the normal spelling??)
Fresh from OBW - Sintered & peac.ock TONED??
Someone, tell me please.... is this from baking on a cookie sheet, or is it chemical... or WHAT?!?!
(Sorry for the period above, in the middle of the bird word... but it wouldn't let me post it with the normal spelling??)
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Comments
of "sintered" or "mis-annealed" planchets.
I believe they were colored/cooked/toned/
you name it...but I'm fairly certain, from the
scans, they are not original Mint issues,
as far as surfaces go......
Fred
BTW, maybe the seller confused 'sintered' with 'cindered' (as in, used a blowtorch) - LOL
coins, of any denomination, is that
scans of them, either on Ebay, or
in an email, sometimes do not capture
the correct luster that a real piece
has.
It's also difficult to verbalize what the
real ones look like - but in general,
they should have original luster, even
if the luster is that "blackish" toning/color.
There is also a continueum (sp?) of intensity,
color, luster, etc. on these coins.
Another clue to look for, is that the rim/edge of
the coin should NOT be as dark as the obv. or
reverse color - although the Blank itself is
sintered/mis-annealed, when the coin is struck,
the color (either reeded or plain) tends to take
out some of the color from the edge - so, it will
be off-color somewhat, but not the same as the
obv./rev.
Bad picture.
San Diego, CA
Fred - I really appreciate you taking the time to try and clarify this anomaly that is difficult to understand without having an example 'in hand'.
I now have one verified picture of the sintered GW dollar & one of the unburnished GW dollar (from board members).
Let me see if I've got this right (please correct me if not):
Unburnished - is darker in color, maybe a little "coppery/grey" looking, not as shiny & lustrous, and a bit "scratchy" looking on the surface.
Sintered - is much darker in color, more of a "charcoal" to blackish tone, but doesn't have the scratchy surface appearance?
And each of these surface issues occur by different methods?
The pictures of these coins does not show it but it is shinny like a regular coin except it looks like it was sprinkle with very tiny black particles.
San Diego, CA
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars • Variety Attribution
San Diego, CA
Now - do you have an unburnished example that you can take a picture of for comparison in the same manner as the second sintered example??
<< <i>MessyDesk - EXCELLENT!! The second picture really helps out a lot more in understaing how this "appears" & what it looks like on a coin. Thank You!
Now - do you have an unburnished example that you can take a picture of for comparison in the same manner as the second sintered example??
Thanks. I don't have an example of a different finish. I don't know that "unburnished" is really a meaningful description. My understanding is that the burnishing slows down the oxidation process, therefore an unburnished coin will just turn dark quicker than a burnished one, and that the long term appearance will be the same.
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars • Variety Attribution
The coin photographs darker than it appears in hand. I'll try to take some lighter photographs of it and post this weekend.
--Jerry
<< <i> I don't know that "unburnished" is really a meaningful description. My understanding is that the burnishing slows down the oxidation process, therefore an unburnished coin will just turn dark quicker than a burnished one, and that the long term appearance will be the same. >>
Yes, my problem too - that is what my previous couple of threads were trying to get at (the difference between sintered vs. unburnished)... but this thread started to get closer to an answer than I've gotten so far.
I have a GW coin that matches pictures of an unburnished coin, but kinda fits the description of what happens to become sintered. The coin I have; however, is not dark grey/black, but it seems to have the 'scratchy' type surface look (due to metal dust?) - it's not actually scratched, it's shiny - but not with the glossy mirror-type shine on the normal coins... it's more of a coppery tone, but not missing clad.
San Diego, CA