Re-worded and expanded notes from class, some helpful info. FINAL UPDATE!

[stinkycheese1]

While I was at my coin conservation, grading and authentication class they gave me a few helpful links that some people here might find useful. I'll update this thread later once I look through more of my notes and possibly find more.

 

I've found one so far, not sure quite what it is. If I remember correctly I thought one of the links had information and pictures.

 

Here's one link I found that was on my notes:

http://www.harrybassfoundation.org/lit/numismaticindexes_list.asp

 

Hope its useful

 

Edit: Perhaps I'll post my notes to the class tommorrow, that should help out a bunch of people.

 

Edit: Ok everyone! Ive expanded and reworded my notes for authentication. I hope this is helpful to you! If anyone needs help or has any questions for the geniune dianostics of key date coins such as the 3 legged buffalo or 1916 D dime let me know, most of these are bill fivaz reference book. I realize some of the dianostics are unclear. If anyone has any questions let me know. If you like my post, let me know and I'll work on tommorrow's and the next days on conservation and grading.SEE POST BELOW!

 

Edit: Now grading and conservation is posted! It would be great if this got to be a WYNTK thread, don't know if it will though. Let me know if you like it. See post below for grading and conservation notes re-worded/rewritten and expanded.

 

[DC Dawg]

If you are a member of the ANA, you can get copies of any of these articles via the ANA Library.

 

Scott

[stinkycheese1]

Notes from authentication, grading, and conservation class taken at the ANA national money show pre-convention seminiar in march, in phoenix.

 

Authentication:

Contempoary counterfeits are circulated

Q: What are altered coins?

~ Date alteration:

A: One or more of the digits are "altered" so the coin can be passed as a more valueable date.

 

TIP --> *First coins made by counterfeit dies look too prooflike (PL), unreal. Worn down counterfeit coins made by counterfeit does look more deceiving.(Worn out dies)

TIP --> Bay Area counterfeits -- (Look up)

~Mint mark alteration:

*The addition or removal of a mintmark to produce a more valueable specimen.

Alterations: Form of a counterfeit coin. Note: This is not the same as surface alteration on a coin.

 

Depressions. --> Depressions are contact marks on an orgininal coin used as a host (sacrificed) on a counterfeit die to make counterfeit coins.

 

Interesting note --> Struck counterfeits are most often seen on gold coins.

Alterations are most commonly seen on all key dates or mintmarks and on most better dates. (Hmm. this doesn't make much sense..)

 

TIP --> Take the How To Detect Counterfeit and Altered US coins ANA correspondence course.

 

TIP --> Most struck counterfeits are uncirculated.

 

Recommend references for further reading:

1) ANA Reprints from the numismatist volumes 1 & 2

2) Copies of Authentication Bureau Column The numismatist, (c.) 1991-2001 and 2007

3) Clippings from coin world and numismatist news

4) Pick up counterfeit coin detector, Bill Fivaz (pocket reference) TIP --> (You can pick these up on ebay. They offer many geniune dianostics for the key dates, including the 1916 D mercury dime and three legged buffalo. Once you know the geniune dianostics its much easier to authentication the altered mint marks or specifics. I got one from the class, a pocket reference from bill fivaz hand signed by him)

 

 

Other references :

1) Misc counterfeit reports

2) National collectors lab

3) ANA cert. service

4) I.B.S.C.C reports and bulletins recourse

5) ANA Mediation service

6) PNG Arbitration service

7) US postal inspector (?? No idea on this one)

8) Federal trade commission

9) Legal action. (?? I think this section was on what to do if you had your coins stolen or if you had a counterfeit coin to give it over to the secret service. Not sure)

 

 

For Struck counterfeits:

~ There are numberous methods used to produce

~ Die struck coins are superior in quality to cast methods

 

For cast counterfeits, some dianostics generally seen on these:

~ pimples and pits (air bubbles)

~ edge seams

~ weight and diameter are sometimes off

 

Electrotypes:

Electrotypes are a soft impression in wax , they are then plated. Lots of ancient coins are done this way. They also often have an edge seam.

 

More about depressions:

~ Depressions have metal flow through them, bagmarks are shiny surrounding the bagmark.

 

The vast majority of spark erosion counterfeits are copper.

 

General counterfeit information:

The more counterfeits made the more loss of detail from that die; so the coin is therefore struck with more force to compensate. Gold coins often have the denticals and on the 1908 S and 1909 S indian cent. (?? Not sure on this one. Notes not clear)

 

Geniune dianostics for several key date coins and alterations:

1) The 1909 S VDB

Geniune specimens should have a die chip in the s, there is a deficient on upper loupe serif, paraellal sides on left. (?)

Check for tooling, scratches, displaced metal polishing or cleaning to conceal evidence

TIP --> embossed mint marks are made by drilling a hole into the coin. Watch out for them.

 

2) 1937 D Buffalo Nickel

Here's a good way to remember the dianostics on a geniune unaltered buffalo nickel of this date.

"If the buffalo's they legs missing"

 

1901 S 25 c -- Watch for seams around the mintmark.

 

1917 Type 1 25 c -- Watch out for re-cut lines

 

1932 D and S 25 c -- Check for seams stuck on coin

 

TIP --> On authentication, you generally cannot deem a struck coin counterfeit with only one depression, generally you need other signs such as spikes from the denticals (Although about 3% of coins with spikes from the denticals are geniune) or multiple depressions.

 

~~ On the 1893 S mint alterations are most common.

 

~~ On the 1894 S $1 look for a die couge on the leg of the eagle. (on geniune pieces)

 

~~ On the 1895 silver dollar the date rises, usually the 5 rises the most.

 

~~ 1928 S $1 peace

Look for light die polish in rays, S mint marks on peace dollars usually sits in a depression, fat.

 

~~~~~~~~~~~~*** ---> Counterfeit gold coins information ~~~~~~~~~~~~*** <-----

There are 2 types of fields on gold coins.

First,

 

The Flat Field Type:

The flat field type is on the :

$1 gold liberty, $2.5,$5,$10, and $20 liberty head and the $3 indian head (Perhaps I mean princess head?)

Flat field coins have denticals, cartwheel luster type.

 

Next,

The sculpted field type:

Indian head $10 gold and saint gaudens $20 gold

Dianostics for counterfeit pieces: Loss of fine detail, weak fat appearance in the letters, numbers, stars etc, denticals seperate, uneven. Known as "toothy" tool marks through the letters, field and numbers.

TIP --> The instructor told me he was able to go on ebay and within 5 minutes find a counterfeit US gold coin from just the look of the coin. On this paticular coin, and on some counterfeit gold US coins, there is a halo or dishing effect on the transition of the field to the denticals. It is a bright circle around inside of the denticals.

 

Characteristics of geniune coins:

(Sometimes the best way to tell if a coin is counterfeit is to know the geniune characteristics. Here are a few of them)

1) Flat even fields

2) good luster and metal flow

3) clear, well formed denticals

4) fine details

5) good relief

6) fine die polish (counterfeits often show loss of detail everywhere)

7) Meets mint specifications for weight, diameter and metal content.

8) die cracks. These are seldon seen on counterfeits

9) denticals are sharp. (TIP! Some counterfeits also have fatty stars. See above)

10) A halo is a bright circle on edge of coin (see above)

 

Other charateristics of counterfeit gold:

1) Loss of relief

2) Raised bumps, ("Pimples")

3) TIP! Depressions have luster in them.

 

~Interesting fact: There was once a infamous counterfeit who "signed" his work with the omega sign. No one knows if he ever was caught, but he counterfeited high relief 20 dollar eagles very well. He also counterfeited $3 indian princess gold. One way you can tell is to look for the omega symbol in the top of "R" on this $3 coin.

 

TIP! Rotate a counterfeit coin under a good light source to spot depressions

TIP! A linear depression is when lint gets between dies. These often are long, thin, with luster. (These are sometimes on geniune coins too, as well as other depressions)

TIP! It's harder to use the fields on the indian head for authentication due to the incuse design. (On the 2 1/2 and 5 dollar pieces). Instead, on geniune specimens, look for die polish lines in the recess of the neck. These are short parallel lines.. On counterfeit specimens, look in stars for toolmarks.

 

TIP! Die polish are fine lines over the entire coin. This is from when the dies were heavily polished at the mint. (??)

 

TIP! $10 indians sometimes have depressions on the letters. That's a good place to look for them.

Contact marks are shiny, where as counterfeit depressions generally have luster in them, metal flow through them, and match the surface characteristics outside of the depression in realative to the depression. They also often have soft, rounded surfaces.

 

Well I hope this helped some of you. IF this is well liked, I'll post and reword my notes on conservation tommorrow, then grading the next day.

 

 

 

 

[bajablu]

Great work there Kevin. Very useful info and well put together. I may have to take some of these classes. Ive heard nothing but great things about them.

 

 

 

A+ on that report card. And a star*

[MikeInFL]

Thank you for sharing your notes!

 

Have you gotten any more reference material?

 

What books/articles do you have in your library?

[stinkycheese1]

Thank you for sharing your notes!

 

Have you gotten any more reference material?

 

What books/articles do you have in your library?

 

I have the PCGS guide to counterfeit detection and grading, bill fivaz pocket reference on key date coins to detect altered coins, bill fivaz book on counterfeit gold, the cherrypickers guide, coin collecting for dummies, and some other stuff.

 

[stinkycheese1]

Wow, I'm really surprised this thread hasn't got more responses. I worked really hard typing this up, I thought more people would be interested. I guess I won't type up the conservation or grading notes.

 

Perhaps its because of my last thread on obessing about things.

[awb]

2) 1937 D Buffalo Nickel

Here's a good way to remember the dianostics on a geniune unaltered buffalo nickel of this date.

"If the buffalo's they legs missing"

spoon = p i s s i n g

 

 

[stinkycheese1]

2) 1937 D Buffalo Nickel

Here's a good way to remember the dianostics on a geniune unaltered buffalo nickel of this date.

"If the buffalo's they legs missing"

spoon = p i s s i n g

 

 

Yeah, I guess it got censored out.

[MarkFeld]

Wow, I'm really surprised this thread hasn't got more responses. I worked really hard typing this up, I thought more people would be interested. I guess I won't type up the conservation or grading notes.

 

Perhaps its because of my last thread on obessing about things.

Kevin, I have no idea how many people are interested in and/or have benefited from this thread. However, I can tell you that the number of replies to a thread doesn't necessarily have anything to do with whether a topic is worthy or not.

 

Often, a nonsense thread receives far more replies than a numismatically important/relevant one does. Also, in quite a few instances many people read threads without replying. So please don't be concerned with how many replies there are. If you want to post additional information, feel free to do so and if you don't feel like it, you shouldn't.

[jesbroken]

Thanks, Kevin. Just read your post, and have found several items informative. I appreciate your effort.

Jim

[bajablu]

Im interested in more Kevin, I know abit about coins, but not everything. Everytime I sign on here I learn something new. I appreciate all the work everyone including yourself contributes to this board and I love the vast amount of knowledge here.

 

 

 

Keep up posting and know Im reading and enjoying your work.

[Doogy]

Kev,

 

I'm pleased to hear you received so much good stuff out of your class! Thanks for sharing it with us, and keep up the good work!

 

 

Doug

[Oldtrader3]

Good thread, Kevin. You are learning a lot of useful information, maybe now with knowledge, you will obsess less?

[WoodenJefferson]

This thread could possibly turn into a What You Need to Know...it has potential.

 

Press on.

[stinkycheese1]

Good thread, Kevin. You are learning a lot of useful information, maybe now with knowledge, you will obsess less?

 

Yes, you'd think that from what all Ive learned I wouldn't obess. But I still obess to this day, today I was worried about a different coin but I did not post a thread about it or discuss it with anyone. I love the hobby anyways, even if I obess a little. Oldtrader3, I hope you enjoyed this thread and hopefully can forget about the other bad ones I've made.

 

Sincerly

kevin

 

[stinkycheese1]

This thread could possibly turn into a What You Need to Know...it has potential.

 

Press on.

 

No kidding? My other thread about counterfeits didn't get in WYNTK despite me contacting supertooth and then who contacted arch. That gives me more determination to do the other 2 on this thread, conservation and grading. I did alot of notes on conservation, but not as many on grading. Today I will post the notes on conservation, then tommorrow grading. You give me hope, it would be great to have this in the WYNTK thread. I'll post the conservation notes right away

 

[stinkycheese1]

General coin tips and conservation, grading.

TIP --> Look for depressions in feathers on indian gold 2 1/2. Often small depressions are found here.

 

General tips:

~ Have direction or purpose in your collection. (Ex. collect not accumulate.[ I accumulate for example ] )

~ When collecting or investing, consider the source of your information before you invest or collect coins in a paticular series.

 

General conservation tips:

~ Although gold is inert (does not tarnish), it is possible for PVC to damage gold over a period of time. (PVC is a chemical that attacks a coin, usually greenish, over a long period of time can etch into the surface of a coin and ruin it. It stands for polyvinylchloride)

TIP --> Use clean hands while working with coins. Do not breathe on coins, the mostiure or spit from your mouth can damage them. Do not use cotten gloves, as they retain moisture. Instead, use nitrile gloves.

~~~***--> Key Care Points<--***~~~

1) Don't eat or drink while working with coins.

2) Avoid transffering residue from one coin to another (cross contaimination)

3) Try not to reuse flips, and polybags.

4) it's best to always wash hands before and after working with coins

5) If you have a coin in your bank despoit box for example, over long periods of time, check coins periodically for enviormental damage from the climate (for example if you live in a humid area. Humidity can be damaging to coins. Best to store coins in a dry, cool enviorment) Don't buy a coin and set it aside without checking it after awhile.

 

 

Holders used for holding coins:

* Use intercept shield technologies for expensive coins.

* Don't use paper envolopes due to glue seams on them. After awhile, the seam can show up on the coin.

* Try not to reuse holders

* Intercept shield holders turn black when ready to discard. They are copper infused.

 

==========Other coin storage options ==============

Coin cabinets:

Try to only use coin cabinets meant for coins..

TIP --> Some problems with these include off gassing of fabrics of glues and from the wood.

 

------Temperature------

Tempeature fluncuations will cause reactions to coins.

1) The ideal temp: Cool (65 degrees to 75 degrees)

Important --> * Do not lay a copper coin on a silver coin, which can cause corrosion. You can buy a cheap humidity and temperature monitor from thompson cigars co for $20.

* Certain tarnish can damage surface of the coins, such as AT toning. AT (artificially toning) digs into luster and can ruin it.

In conservation, the most important thing is protecting the coin and its orginal surfaces, *not* improving the eye appeal. Goal is for example to reveal the orginal surface of the coin. Ask yourself, "What are the underlying surfaces like?" Don't conservation coins you dont know much about the coins, or methods of conervation. Be extra careful about conservating copper.

TIP --> "Neutralize" a coin after a dip, this is very important. Some natural interactions include copper which interacts with silver coins can galvanize them .

 

------------------------------Chemical safety and commercially sold products available to the product. (note : NCS (numismatic conservatoin services) has many products that are not available to the mass market.It's best to send the coins into them for the most serious jobs, rather than risk it and doing it yourself) ------------

Material safety data sheets MSDS. Important --> Don't pour chemicals down your drain!

 

-------Chemicals for conservation available to the public ----------------

*******E-Zest (Jewel luster)

* aka a jewrly cleaner rinse. It's best to use de-ionized water with baking soda to neutralize finish with rubbing alcohhal and then pat dry, rinse off.

* E-zest is acidic

* It also can weaken the luster

* changes color of the coin

 

-------------------------------------------

*******MS-70

* It's effective in removing many residues. Good for lightening copper coins.

* However, it can leave a residue on a coin. Must rinse after use. TIP --> Rinse, then neutralize.

 

-----------------------------------------

Lacquer thinner:

* removes lacquer

* Use with caution, it can be dangerous.

 

Bleach:

* Do not use, can damage coins.

 

TIP --> Vinegar, olive oil can remove dirt and encrustations from ancient coins dug up. Also, warm sopay water is good to remove dirt, be sure to rinse after.

 

The evaulation process:

* Examine the entire coin under ideal lighting.

* Ask yourself, "What if any visible problems exists?"

* Ask yourself, "Is the surface problem detrimental to the coin?" If not, don't conserve it.

 

On some large cents, red enviormental damage can occur when PVC turns powdery grey it etches into the surface of the coin, damaging it. Often, PVC an turn powdery grey. So it's something to look out for.

TIP --> Each time a coin is dipped it dulls the luster. It's best to dip in acetone, then take a q-tip and brush the denitcals of the coin.

 

Tip for using jewel luster:

I once took a knife to my 1913 gold british sovereign to remove a copper spot. The teacher told me actually at NGC he often sees copper spots that were removed by a razor blade that someone scratched off. Here's an easier way to remove a copper spot on a gold coin:

Using jewel luster - Use a toothpick on a gold coin where the copper spot is and put a very small light amount of jewel luster on the tip of the toothpick (just a little dot), dab gently on the copper spot. Be sure to use diuluted dip of jewel luster, let teardrop dry and then come off. The acid will eat into the copper spot, remove it, and not damage the gold underneath.

 

TIP --> It's best to use a 75 watt *name brand* bulb. Do not use cheap knock-offs.

 

Another way (and more risky way) of removing a copper spot is that some people take a blowtorch and burn it off! . Then they reapply the PVC skin.

 

Some things COIN DOCTORS don't want you to know

* Coin doctors put baking soda and water and swab (using a swab) rub the coin to lighten up the surfaces of the coin.

Some also use ammonia on US mint residue (toning) from residue from the plastic.

 

----------------------------------------------------------------------------

Coin grading

----------------------------------------------------------------------------

Market grading --> Market grading describes the state of perservation with modifiers.

The most important areas of grading to take into consideration are:

1) Marks

2) Strike of the coin

3) The luster of the coin

4) The eye appeal (NGC gives the coins with the most eye appeal a star, as these are PQ in their opinion)

TIP --> On number 1) , marks, it is important to note that size, severity of the mark, and also the location of the mark factors into the overall grade of the coin. For example, a noticiable bagmark on the face of miss liberty on a gold piece would take a bigger hit to the overall grade than a bagmark some other locations. Gold also, since its softer, usually gets more leniacy on grade.)

Relative to a "Perfect" examlpe (MS70) -- Is dependent on the coin type and issue.

5) The grade of a coin is usually dependent on the marketplace.

6) Gold is often allowed more marks than other metals due to its softness.

TIP --> Relative softness = Gold > Copper > Silver > Nickel.

Older type coins are allowed more friction.

TIP ---> Usually, the reverse of a coin grades higher. Also, sometimes the obverse grade predominates.

* Consistent grading is the key. It's best to try and be more consistent than anything else in grading.

 

* Lighting: Make the coin light dynamic under a good light source . Do not use flouresent lighting when buying a coin since these do not often show all the marks of a coin.

* A halogen light is usually too bright to use for coins. Use an indcandescent

 

------Magnification-------

It's best to use a triplet loupe. Low power is best for grading (5-7x) and higher power good for vareties, and counterfeit detection such as and alterations. (10-20x)

TIP --> Use a "safety net", such as a towel, or padded velvet tray to catch the coin.

 

-----Viewing a coin----~

~ Hold the coin by the edge and place the coin 8 to 12 inches under a light source. View the coin without magnification , the obverse, then the reverse, and the edge, use a focal point (first pointe looked at) to determine the grade. You can also change the angle of light to reveal scratches on a coin.

TIP --> Strong strikes on a coin usually grade higher. Use strike of a coin when determining a coins grade.

~ Friction marks are when one side of a coin hits another.

TIP --> Location is paramount when determinng bagmarks or scratches on a coin. (See above)

(Wear) rub is often dark on coins. Friction on a coin his lighter, shinier.

 

~~~~~~ Die states ~~~~~~~~~

Prooflike dies --> A new die without evidence of metal flow.

SMPL (Semi-proof like) die -- > New die beginning to show wear.

Frosty luster (on coin) die --> die with notacable flow lines, cartwheel luster effect.

Satin luster (As seen on some early date saint gaudens coins) - Die with little evidence of metal flow.

Flat luster --> Die without flow lines or worn die.

 

TIP --> San fransico mint coins are generally well struck.

 

Full split bands designation on mercury dimes -- Shows no damage or interruption on both bands

Full bell lines on franklin half dollar - Both set of lines are shown, not seperated. May allow a hit or light scratch on these on MS65 condition

 

TIP to watch out for -- > (On full split band mercury dimes) Some coin doctors sometimes may use a razor blade on the bands to make them look like full split bands. you can detect this since it usually is too shiny.

 

TIP -- > On the standing liberty quarter, when the shield turns grey its usually AU condition.

TIP -- > Intial points of wear on a coin: generally the highest opints of the coin , also color change (luster disturbance) has an effect, then design flattening, . Circulated coins may have a darker color.

 

**TIP -- > It's best to learn to grade on the highest grade coins then work your way down to the lower grade coins when examining coins.

TIP --> Die polish often goes underneath letters, where as hairlines are often over the letters, you can rotate a coin around to find the hairlines.

 

As for rim filing, make them light dynamic, they are often shiny, just roatate under light to see filing. TIP -- > A whizzed coin is when metal flow on a coin goes in all directions instead of in and out like a clock hand.

 

Good references:

* Offical ANA grading standards for united states coin. (6th edition)

 

 

OK everyone, here it is. I've included both conservation and grading in this one.

[jesbroken]

Great post, Kevin. Thanks again,

Jim

[Just Bob]

Good notes, Kevin - lots of good information! (thumbs u

 

This line in particular stands out:

 

<When collecting or investing, consider the source of your information before you invest or collect coins in a paticular series>

 

In the 80's, I lept before I looked, and most of the "investment" coins that I bought because of the hype by a particular company are still not worth what I paid for them.

[Oldtrader3]

Kevin, I have no issues with you. Just try to enjoy your collection.

[dooly]

Cheers for the information stinky .. its just a shame i cannot afford any US gold

 

all the best dooly

[rrantique]

General coin tips and conservation, grading.

TIP --> Look for depressions in feathers on indian gold 2 1/2. Often small depressions are found here.

 

General tips:

~ Have direction or purpose in your collection. (Ex. collect not accumulate.[ I accumulate for example ] )

~ When collecting or investing, consider the source of your information before you invest or collect coins in a paticular series.

 

General conservation tips:

~ Although gold is inert (does not tarnish), it is possible for PVC to damage gold over a period of time. (PVC is a chemical that attacks a coin, usually greenish, over a long period of time can etch into the surface of a coin and ruin it. It stands for polyvinylchloride)

TIP --> Use clean hands while working with coins. Do not breathe on coins, the mostiure or spit from your mouth can damage them. Do not use cotten gloves, as they retain moisture. Instead, use nitrile gloves.

~~~***--> Key Care Points<--***~~~

1) Don't eat or drink while working with coins.

2) Avoid transffering residue from one coin to another (cross contaimination)

3) Try not to reuse flips, and polybags.

4) it's best to always wash hands before and after working with coins

5) If you have a coin in your bank despoit box for example, over long periods of time, check coins periodically for enviormental damage from the climate (for example if you live in a humid area. Humidity can be damaging to coins. Best to store coins in a dry, cool enviorment) Don't buy a coin and set it aside without checking it after awhile.

 

 

Holders used for holding coins:

* Use intercept shield technologies for expensive coins.

* Don't use paper envolopes due to glue seams on them. After awhile, the seam can show up on the coin.

* Try not to reuse holders

* Intercept shield holders turn black when ready to discard. They are copper infused.

 

==========Other coin storage options ==============

Coin cabinets:

Try to only use coin cabinets meant for coins..

TIP --> Some problems with these include off gassing of fabrics of glues and from the wood.

 

------Temperature------

Tempeature fluncuations will cause reactions to coins.

1) The ideal temp: Cool (65 degrees to 75 degrees)

Important --> * Do not lay a copper coin on a silver coin, which can cause corrosion. You can buy a cheap humidity and temperature monitor from thompson cigars co for $20.

* Certain tarnish can damage surface of the coins, such as AT toning. AT (artificially toning) digs into luster and can ruin it.

In conservation, the most important thing is protecting the coin and its orginal surfaces, *not* improving the eye appeal. Goal is for example to reveal the orginal surface of the coin. Ask yourself, "What are the underlying surfaces like?" Don't conservation coins you dont know much about the coins, or methods of conervation. Be extra careful about conservating copper.

TIP --> "Neutralize" a coin after a dip, this is very important. Some natural interactions include copper which interacts with silver coins can galvanize them .

 

------------------------------Chemical safety and commercially sold products available to the product. (note : NCS (numismatic conservatoin services) has many products that are not available to the mass market.It's best to send the coins into them for the most serious jobs, rather than risk it and doing it yourself) ------------

Material safety data sheets MSDS. Important --> Don't pour chemicals down your drain!

 

-------Chemicals for conservation available to the public ----------------

*******E-Zest (Jewel luster)

* aka a jewrly cleaner rinse. It's best to use de-ionized water with baking soda to neutralize finish with rubbing alcohhal and then pat dry, rinse off.

* E-zest is acidic

* It also can weaken the luster

* changes color of the coin

 

-------------------------------------------

*******MS-70

* It's effective in removing many residues. Good for lightening copper coins.

* However, it can leave a residue on a coin. Must rinse after use. TIP --> Rinse, then neutralize.

 

-----------------------------------------

Lacquer thinner:

* removes lacquer

* Use with caution, it can be dangerous.

 

Bleach:

* Do not use, can damage coins.

 

TIP --> Vinegar, olive oil can remove dirt and encrustations from ancient coins dug up. Also, warm sopay water is good to remove dirt, be sure to rinse after.

 

The evaulation process:

* Examine the entire coin under ideal lighting.

* Ask yourself, "What if any visible problems exists?"

* Ask yourself, "Is the surface problem detrimental to the coin?" If not, don't conserve it.

 

On some large cents, red enviormental damage can occur when PVC turns powdery grey it etches into the surface of the coin, damaging it. Often, PVC an turn powdery grey. So it's something to look out for.

TIP --> Each time a coin is dipped it dulls the luster. It's best to dip in acetone, then take a q-tip and brush the denitcals of the coin.

 

Tip for using jewel luster:

I once took a knife to my 1913 gold british sovereign to remove a copper spot. The teacher told me actually at NGC he often sees copper spots that were removed by a razor blade that someone scratched off. Here's an easier way to remove a copper spot on a gold coin:

Using jewel luster - Use a toothpick on a gold coin where the copper spot is and put a very small light amount of jewel luster on the tip of the toothpick (just a little dot), dab gently on the copper spot. Be sure to use diuluted dip of jewel luster, let teardrop dry and then come off. The acid will eat into the copper spot, remove it, and not damage the gold underneath.

 

TIP --> It's best to use a 75 watt *name brand* bulb. Do not use cheap knock-offs.

 

Another way (and more risky way) of removing a copper spot is that some people take a blowtorch and burn it off! . Then they reapply the PVC skin.

 

Some things COIN DOCTORS don't want you to know

* Coin doctors put baking soda and water and swab (using a swab) rub the coin to lighten up the surfaces of the coin.

Some also use ammonia on US mint residue (toning) from residue from the plastic.

 

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Coin grading

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Market grading --> Market grading describes the state of perservation with modifiers.

The most important areas of grading to take into consideration are:

1) Marks

2) Strike of the coin

3) The luster of the coin

4) The eye appeal (NGC gives the coins with the most eye appeal a star, as these are PQ in their opinion)

TIP --> On number 1) , marks, it is important to note that size, severity of the mark, and also the location of the mark factors into the overall grade of the coin. For example, a noticiable bagmark on the face of miss liberty on a gold piece would take a bigger hit to the overall grade than a bagmark some other locations. Gold also, since its softer, usually gets more leniacy on grade.)

Relative to a "Perfect" examlpe (MS70) -- Is dependent on the coin type and issue.

5) The grade of a coin is usually dependent on the marketplace.

6) Gold is often allowed more marks than other metals due to its softness.

TIP --> Relative softness = Gold > Copper > Silver > Nickel.

Older type coins are allowed more friction.

TIP ---> Usually, the reverse of a coin grades higher. Also, sometimes the obverse grade predominates.

* Consistent grading is the key. It's best to try and be more consistent than anything else in grading.

 

* Lighting: Make the coin light dynamic under a good light source . Do not use flouresent lighting when buying a coin since these do not often show all the marks of a coin.

* A halogen light is usually too bright to use for coins. Use an indcandescent

 

------Magnification-------

It's best to use a triplet loupe. Low power is best for grading (5-7x) and higher power good for vareties, and counterfeit detection such as and alterations. (10-20x)

TIP --> Use a "safety net", such as a towel, or padded velvet tray to catch the coin.

 

-----Viewing a coin----~

~ Hold the coin by the edge and place the coin 8 to 12 inches under a light source. View the coin without magnification , the obverse, then the reverse, and the edge, use a focal point (first pointe looked at) to determine the grade. You can also change the angle of light to reveal scratches on a coin.

TIP --> Strong strikes on a coin usually grade higher. Use strike of a coin when determining a coins grade.

~ Friction marks are when one side of a coin hits another.

TIP --> Location is paramount when determinng bagmarks or scratches on a coin. (See above)

(Wear) rub is often dark on coins. Friction on a coin his lighter, shinier.

 

~~~~~~ Die states ~~~~~~~~~

Prooflike dies --> A new die without evidence of metal flow.

SMPL (Semi-proof like) die -- > New die beginning to show wear.

Frosty luster (on coin) die --> die with notacable flow lines, cartwheel luster effect.

Satin luster (As seen on some early date saint gaudens coins) - Die with little evidence of metal flow.

Flat luster --> Die without flow lines or worn die.

 

TIP --> San fransico mint coins are generally well struck.

 

Full split bands designation on mercury dimes -- Shows no damage or interruption on both bands

Full bell lines on franklin half dollar - Both set of lines are shown, not seperated. May allow a hit or light scratch on these on MS65 condition

 

TIP to watch out for -- > (On full split band mercury dimes) Some coin doctors sometimes may use a razor blade on the bands to make them look like full split bands. you can detect this since it usually is too shiny.

 

TIP -- > On the standing liberty quarter, when the shield turns grey its usually AU condition.

TIP -- > Intial points of wear on a coin: generally the highest opints of the coin , also color change (luster disturbance) has an effect, then design flattening, . Circulated coins may have a darker color.

 

**TIP -- > It's best to learn to grade on the highest grade coins then work your way down to the lower grade coins when examining coins.

TIP --> Die polish often goes underneath letters, where as hairlines are often over the letters, you can rotate a coin around to find the hairlines.

 

As for rim filing, make them light dynamic, they are often shiny, just roatate under light to see filing. TIP -- > A whizzed coin is when metal flow on a coin goes in all directions instead of in and out like a clock hand.

 

Good references:

* Offical ANA grading standards for united states coin. (6th edition)

 

 

OK everyone, here it is. I've included both conservation and grading in this one.

 

 

This is a great post Kevin, worthy of a WYNTK

[rbrown4]

Kevin,

 

A very good post with great information.

 

Rey