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Ph of skin oils/sweat in silver


#1

I sold a silver ring to a friend and it blackened within days. He
says this always happens with his silver rings. Is it something to do
with the ph of skin oils/sweat? He doesn’t work with any chemicals
etc.

laura cowan
judaica designer and silversmith
website: www.lauracowan.com


#2

Hi Laura, I read an article that said a persons diet can make a
difference, especially if they have spicy foods such as cayenne.
Medications can also have an effect, like a sulfur based
antibiotics. It depends upon your chemical make up, how you
personally process the food and can change. It’s like some people
can eat garlic and others shouldn’t! OR everyone should! Yum.

Marta


#3

Actually, I believe that it’s a sulfur reaction. There’s a trace of
sulfur on your skin, and some people have more than others.

Just as an FYI, though, your skin has an average pH of 5.5, making
it acidic. There’s a handcream and soap out now to neutralize the
acidity of your skin, making it a neutral 7. I saw an ad for it
yesterday in a scrapbooking magazine. I have no idea if this would
have any jewelry applications, though.

Elizabeth Schechter
R-F-X Studios
6400 Baltimore National Pike
Suite #170-A, #445
Baltimore, MD 21228
410-719-8712

"He who works with his hands is a laborer.
He who works with his hands and his head is a craftsman.
He who works with his hands, his head, and his heart is an artist."
St. Francis of Assisi


#4

Hi Laura, Your first guess is correct! Some people have more acidic
sweat than others. My Aunt Doris, for example, has never been able
to wear wristwatches made from base metal. They corrode within a
matter of weeks.

One of my college friends had the same trouble. His collection of
broken watches was legendary. :slight_smile: All of his sterling silver
jewelry was black. The only silver rings he could wear were pieces
which his father (who was a dental tech) used to cast from a
palladium/silver alloy. That was a good option in 1985, when
palladium was selling for $50/oz… I doubt that anyone makes
palladium/silver dental alloy these days… The last time I
checked, the spot price on palladium was higher than either platinum
or gold. Palladium was once considered a cheap alternative to
platinum. No more. :slight_smile:

You could try coating your friend’s ring with jeweler’s laquer, or
with ethanol-based Mastic varnish. (The latter should be made from
dry gum Mastic and pure, not denatured, ethyl alcohol. The prepared
Mastic varnish which is sold for oil painting is solved in
turpentine, and is not suitable for use on jewelry.) Coatings of
this sort have to be replaced from time to time.

-Pete-


#5

I just had a customer bring a silver ring in that she purchased for
her granddaughter. She said her granddaughter wears other silver
rings and they don’t turn her finger black like this one. I made the
ring so I know its good silver! I am going to clean it up (looks
gunky) and polish it. Then wash it good with soap. I’ll tell her if
she isn’t happy with it, I’ll gladly give her a refund. I’ve copied
this thread to give her so she can see it is a real problem. I’ve
found it more of a problem with young girls. Maybe they’re on Acne
medication or eat too much junk food? :slight_smile:

I’d much rather have a happy customer than win an argument. It’s
just that she thinks it’s cheap silver or not silver.

Susie Morgan
Elegant Metal Creations


#6

Hi Every One, I have learned many years ago that high acid levels in
the body tarnishes Sterling much faster that those with a lower
acidic body. Someone posted that it may be diet related. This is
true to some degree. When one has an acidic body, the way to
neutralize it is to eat alkaline foods. Grapes and pears can turn
an acid body and even one who suffers with heartburn into an
alkaline system quickly, alleviating the acidity in the stomach and
the acid levels while perspiring. The higher the acid level in
one’s body, the faster Sterling Silver turns black. After years of
research it isn’t any pear that will turn an acid stomach into
alkaline bringing about a neutralized pH balance, it is the Japanese
Pear which is large, round, and juicy. So, diet does matter but some
people just have a higher acid level in their bodies than others.
The best and cheapest way to clean it and have it remain shiny for a
longer period of time is using tooth paste and just the fingers to
rub it over the Sterling, then rinse thoroughly or the tooth paste
my burn the skin. Hope this helps. This just goes to show we are all
made differently.

Bj


#7

haircare products or bleach products or mineral hot springs
can affect sterling.


#8

Hi – I remember reading somewhere, Hoover catalog? – that hormonal
cycles will affect skin/metal interaction. A teenage girl?
Hormonal ups and downs? Sounds right to me! Actually, my skin is
very sensitive to all metals, including pt, 22kt yellow, and
stainless steel, but not all the time. I’m sure that if I tracked
it for several months, there would be a clear pattern. Do check the
Hoover catalog articles! Elna in Berkeley, where the rain is pouring down…


#9

With respect, (which means I’m going to disagree with someone
vehemently) The Ph of different peoples skin varies by minute
amounts. Hardly enough to matter in fact. Diet certainly plays a part
in what is contained in the sweat the skin produces (try eating
garlic raw - your skin will smell of it for a while) but it is just
not possible to alter the Ph of the human body by eating different
things.

The human body has a continual Ph throughout, except in very
specific organs. It’s very high, for example in the stomach which
produces hydrochloric acid, saliva is slightly alkaline - but blood,
bone and tissue remain the same Ph. Skin has a Ph between 4.2 and 5.6
(slightly acidic)

The Ph of skin is, in any case, dependant on the bacteria that
inhabit the skin surface and break down the secretions (sweat, sebum
etc.) Constant washing can destroy these bacteria leading to problems
(ask any theatre nurse!) We need an acidic skin to protect ourselves!

Tony Konrath


#10

Tony, I may be mistaken here but I seem to remember that pH is
calculated by taking the negative log of the hydrogen ion
concentration (diggin’ way back here!) If that’s the case, then the
difference between 4.2 and 5.6 would actually be quite
large(logarithmic like the Richter scale). I don’t really know if
that difference would be large enough to significantly affect the
oxidation of metals from one person to another. I’m new to metal
craft. I’m sure there are other variables at work as well…nothing’s
ever simple these days!

Anyway, apologies if my memory or my math is weak…it’s been years
since I did that sort of work! -Mike

Mike Dibble
Black Horse Design
New Greyhound & Celtic Designs Now on Display!
10% of retail sales support rescues.
www.black-horse-design.com


#11

Just my 2 cents’ worth: I remember reading some time back that
frequently those people who turn silver jewelry black in a very short
time have some chemical on their skin, reacting with the silver (a
very reactive metal.) Sometimes it is cosmetics, sometimes residue of
soap, etc. Sorry I don’t recall the source of the info., but it MIGHT
have been in one of Stuller’s wonderful newsletters.

David Barzilay, Lord of the Rings


#12

MMMMM… Maybe you’re right. but the lower you get on the scale the
greater the difference in ph points. It’s still very mildly acidic.
(Neutral is 7, the stomach is 1 or 2.)

Whatever, I still contend that you can’t change shin Ph by eating
Mirolban plums!

Tony Konrath


#13

Hi guys, You’re gonna think I’m nuts. I just pulled out my old
chemistry text. Here’s the scoop on pH. pH is as Mike says the
negative logarithm to the base toen of the hydrogen ion concentration
{H3O+) in solution.

pH = -log10(H3O+)

heres a list of typical strengths,

pH    Substance
-1    concentrated hydrochloric acid
0
1
2    stomach acid, lemon juice
3    orange juice
4    soda water, tomato juice
5
6    rain water, milk
7    pure water
8    blood, sea water, baking soda solution
9
10    regular soap
11
12    household ammonia
13
14    concentrated sodium hydroxide solution
15    drain cleaner

Regards,
Dave