The colors of copper Publique Deposited
- From johnmenc@optonline.net Wed Apr 03 06:30:34 2013
Return-Path: <johnmenc@optonline.net>
X-Sender: johnmenc@optonline.net
X-Apparently-To: colonial-coins@yahoogroups.com
X-Received: (qmail 87013 invoked from network); 3 Apr 2013 13:30:32 -0000
X-Received: from unknown (10.193.84.163)
by m9.grp.bf1.yahoo.com with QMQP; 3 Apr 2013 13:30:32 -0000
X-Received: from unknown (HELO ng3-vm5.bullet.mail.gq1.yahoo.com) (98.136.219.31)
by mta3.grp.bf1.yahoo.com with SMTP; 3 Apr 2013 13:30:32 -0000
X-Received: from [98.137.0.88] by ng3.bullet.mail.gq1.yahoo.com with NNFMP; 03 Apr 2013 13:30:32 -0000
X-Received: from [10.193.94.44] by tg8.bullet.mail.gq1.yahoo.com with NNFMP; 03 Apr 2013 13:30:32 -0000
Date: Wed, 03 Apr 2013 13:30:31 -0000
To: colonial-coins@yahoogroups.com
Message-ID: <kjhatn+i1v0@eGroups.com>
In-Reply-To: <kjh3dm+ru3q@eGroups.com>
User-Agent: eGroups-EW/0.82
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: quoted-printable
X-Mailer: Yahoo Groups Message Poster
X-Yahoo-Newman-Property: groups-compose
X-Originating-IP: 96.56.209.230
X-eGroups-Msg-Info: 1:12:0:0:0
X-Yahoo-Post-IP: 96.56.209.230
From: "colonialjohn" <johnmenc@optonline.net>
Subject: The colors of copper
X-Yahoo-Group-Post: member; u=111282553; y=_0rdSt_GE_6AyqLPdAC2pCl4Pz5mXCkJnGHiP6ocR5LvofIvLCGtyy-W-Q
X-Yahoo-Profile: colonial_john_c4
For those attending the EAC XRF talk this bit of information may help prior=
to this discusssion. When we think of copper corrosion on our coins we gen=
erally think of "green color." Copper corrosion can take on various colors =
- so here is a typical suite of colors:
1. Cuprite (Cu2O)=3D Red-brown color.
2. Atacamite (Cu2(OH)3Cl) =3D Yellow-green
3. Malachite (Cu2(OH)2CO3) =3D Green
4. Chalcocite ((Cu2S) =3D Dark Brown to Black
5. Brochantite CuSO4=B73Cu(OH)2 =3D Green to bluish green
Normally you start with Cu2O and then atacamite and brochantite normally fo=
llow if the corrosion progresses further along ... so we normally see green=
/red to brown to black (final state).
Phil - the best paper I have seen on this subject involving a billon alloy:
http://link.springer.com/article/10.1134%2FS2070205110061012#page-1
JPL
--- In colonial-coins@yahoogroups.com, "colonialjohn" <johnmenc@...> wrote:
>
> Mark Fashian & XRF ... tempting ... I am sure there will be alloy differe=
nces between a 1794 Starred Reverse (S-48) and a 20thC Lincoln Cent ...
>=20
> --- In colonial-coins@yahoogroups.com, Ray Williams <njraywms@> wrote:
> >
> > Hi Guys!
> > On our C4 website is information about the upcoming EAC=20
> > Convention. A direct link to it is:
> >=20
> > http://www.colonialcoins.org/upcoming_meetings_and_events.htm
> > Ray
> >
> - 2013-04-03
- 1
