Grading Services for the Amateur Collector

There's really no reason for anyone to use any other TPG than the top four at this point in time.

 

Log in or Sign up to hide this ad.

How COULD an overstrike be an MS70? It starts out on an imperfect "planchet".

 

Technically 70s are supposed to be as struck. I thought the same but seeing the final products there are some that are deserving

 

I'll address the easy one first: TheFinn, posted: "How COULD an overstrike be an MS70? It starts out on an imperfect "planchet"."

@baseball21 answered this. Origuinally, "For condition 70, the coin must be exactly as it left the dies,aexcept for a slight mellowing of the color." Condition 70 means perfect Mint State." That's why TPGS allow small struck thru's on SE graded MS/PR-70.

Mainebill, posted: "I feel the big 2 are about 80% accurate most of the time."

Then he starts to list many of his experiences making up his claim of 20% grading errors. If you have ever been in a coin grading seminar (even the advanced class) the entire week could be wasted on stories such as those posted by this member.

First, let me say that the TPGS are far from perfect. Additionally, our different personal experiences and skill levels determine how we rate a particular TPGS opinion. That's why whenever I read stories like those posted above I am amused. No, actually when I see that someone questions the grade assigned by a major TPGS I usually HOWL WITH LAUGHTER!

That's because from personal contact in many classes and at coin shows the sad fact is that most people cannot grade. Most small time dealers couldn't detect a cleaned coin if you scrubbed it with Brillo while the watched!!

IMO, the number of under graded coins is virtually non-existent because someone much smarter buys it and it gets up graded. Only the over graded coins should be a problem but we don't hear much complaining about them do we. So IMO, the 20% number mentioned is incorrect. It is probably closer to 2% and those are the over graded slabs.

Here is a clue for all of us. The TPGS's need your business. They play so "loosey-goosey" in order to straight grade that old timers as me sometimes choke. Therefore, know that when you get a coin back in a details grade IT HAS A REAL PROBLEM whether you can find it or not!

 

Q. If you get a details coin back and you decide to resubmit it until it comes back straight graded, and it takes you two or three resubmits to get there, does that still mean it originally had a real problem, or does it mean that the details grade was originally given on something not all people would consider needing a details grade? Especially if you as the coin owner felt it was wrongly graded details in the first place?

 

"Details" is a subjective thing. Especially with regard to cleaning.

Lets take some easy examples first. What is the smallest scratch you will tolerate on a coin when you buy it? How about this: How much rim damage or nicks do you tolerate on a dollar or $20? What about a tiny rim file that is hidden completely by the insert? How upset are you when you discover a problem on a raw coin that you missed? What about a problem on a slabbed coin that you think the TPGS missed?

Now to cleaning. Most vintage coins have been cleaned before. 18th and 19th Century coins especially. The coins that tone down are often considered market acceptable. When I was coming op, I thought any coin w/hairlines was cleaned. That is not the case. It is only the coins that are off color (chem. etched) or those that exhibit mostly parallel hairlines that are improperly cleaned. Now how much of a detraction should they be before the coin is "detailed." Those guys at the grading service must do this every minute! Additionally, what bothers one may not bother another.

So, IMO it is unfortunate if a detailed coin can be straight graded when sent in again but that's life. It is due to a lack of strict standards. That's the same thing that happens when an AU is first graded MS and then graded AU or when just the opposite happens.

 

More subjectivity than lack of strict standards. A lot of details things in terms of how much is tolerable is one of those “I’ll know it when I see it”. You could argue that if everything was detailed then it’s less of an issue, but no one really wants grading like that.

 

7. Ed who?

 

So I took the $2.5 and $5 Indian heads into the local coin shop today. The owner gladly took a look at each. He had no doubt the $2.5 was authentic and complimented it being a beautiful coin. He was less sure about the $5...

The good: weight was spot on, tested as 90% gold, had good detail.

The bad: color is off (too yellow, which is obvious), didn’t have the right sound when lightly dropped on desk (keep in mind this is a common date vf30), possible slight raise in field directly in front of the eye on the obverse.

I don’t know if it’s even worth sending in. Sounds like it may be a high quality counterfeit which is only worth spot (being generous) which in all honesty is about all a genuine in this condition is worth anyway. He didn’t want to say it was counterfeit but the color especially concerned him.

He thanked me for bringing them in and i bought a nice Indian head cent that I needed for my set to thank him for the trouble.

 

Can someone refer me to information which explains how to tell if my gold coins have been cleaned? I have 2 safety deposit boxes filled with mostly graded coins, however there are about 50 ungraded gold pieces. I'm mostly interested in my 1876 CC $20 Liberty. How can I tell if my Grandfather cleaned it before he put it in the safety deposit box? THANK YOU!

 

Get your self a 10x loupe and examine the surfaces and look for fine hairlines. Don't get them confused with die polishing lines. Cleaning hairlines generally extend off the surfaces and on to the details of the coin. That's one way to see if the coin had light cleaning (wiping with soft cloth).

Generally, a harsh cleaning is easy to spot without a loupe. Hope that helps a little. I hope some other members will give you additional things that indicate a cleaned coin.

 

Easy(for many of us)!

1. Put an incandescent lamp on a table. Turn out the other lights and close the blinds/drapes so the room gets as dark as you can get it.

2. Take out 2-3 of the highest TPGS graded gold coins you have for each denomination. Examine them as I wrote below in #5. Ignore the reflection from the plastic.

3. Now take an ungraded coin and compare the color of the ones in the slab.

4. Next, examine the raw coin using 5-10X glass. Hold the glass next to your eye and bring the coin close until it is in focus.

5. Slowly turn the coin and tip it back and forth just a little at the same time you turn it through at least 240 degrees.

You are looking for fine, shiny, PARALLEL hairlines. Very often, a cleaned coin will flash and change color the moment the parallel lines become horizontal to the position of the light.

Let us know what happened.

 

THANK YOU for the "cleaning" advise. I've been reading so much about coin grading that I think I've lost confidence in my basic opinions. I followed the guide you gave me and had a lot of fun. Most of the gold coins I viewed were, in my unprofessional opinion, not cleaned. However, that was not true for the silver coins. I became frustrated with the silver and immediately decided to look for key date coins, and then sell the rest in order to reinvest in gold. Ha. The good news for me is that I learned today that there is a "third" safety deposit box I did not know about, and it contains mostly graded St. Gaudins and Double Eagles. I'm thinking about focusing on the gold coins, selling the silver, and reducing the number of safety deposit boxes. It's been fun viewing the first two boxes because they contained Series EE bonds, certified paper money, lots of 22K golden nuggets, etc. I learned something about myself I did not know. I love gold pre-1933 gold coins. THANK YOU for helping me learn more about coins . . . and about myself.

 

What would take the mint bloom off a gold coin and not leave any fine scratches? Gold should be inert, but there will be a bit of silver or copper in the alloy.

 

Are you asking about its "Mint Luster?" If so, wear, chemical cleaning, and altering its surface by applying a foreign substance could do it.

 

Yes a sheen on mint coins. What chemicals would destroy this on a gold coin?

 

Only one acid can etch gold so most of the luster loss is due to wear or some chemical coating. These additives fall under the name of "putty." They are dissolved in a "carrier chemical" that evaporates.

 

Thanks so much. I doubt that people are using aqua regia to clean their coins. The idea should be to leach off crud and leave the coin alone. So any acid that would attack the crud would do, but something seems to be destroying the mint lustre. I was wondering if a strong mineral acid, say like nitric, might attack and leach out some of the alloying metal? Perhaps that might kill the mint lustre?

What's in this putty? The carrier just evaporates and leaves a coating? Yes a coating would really change the lustre and leave no scratches. Presumably a bath in acetone or rubbing alcohol would remove such a coating and restore any mint bloom, if there was any left in the first place.

Approached from another direction: Are there high magnification photos of coin surfaces? I'm not sure what exactly would cause the specular reflection that i'm seeing and calling mint lustre. On the coin's surface could there be local "mountains" with a height of around light's wavelength or so? They might produce the mint lustre I'm seeing by reflecting light off many "mountain" sides at once as the coin is played in the light. Such "mountains" would be worn down with very little wear. This could explain "AU Details, Cleaned" on the slabs where the mint lustre is visible between the letters in the legend but not in the main field. The raised letters might protect the adjacent areas from the rubbing that would erode the "mountains". If that's true there should be scratches in the surface from the rubbing. I don't see that. Are the scratches too tiny for me to see on a "lightly cleaned" coin? Thanks again for your help.

 

Most tend to forget that mercury can amalgam with gold to form a whitish gray colorarion. Amalgams are different from acid reactions because gold and mercury ( 2 metals) interact with metallic bonding rather than the more common covalent or ionic bonding as metallic bonding shares electrons collectively as clouds rather than specific orbital bonding. Mercury is/ or rather was , a material that was very common, especially in schools, metallurgist, assayists, etc. as well as dentistry. Here is an article that talks about gold amalgams corrosion.

http://journals.sagepub.com/doi/abs/10.1177/00220345700490023401?journalCode=jdrb

I have taken photos of the surface of morgan dollars to illustrate the differences in toning characteristics, but only in the range of 100-400X. I no longer have access to SEM, but if someone serious wanted to do higher resolution photos, this would be the way to go.

Morgan on left, peace on rt. 100X



Then to show the higher peaks on the Morgan and the more acute angles to produce more light variations in toning , This is a 400X of a Morgan. I tried a 1000X, but the light and depth of field of the Light microscope was too little. thus someone needs to do studies with a SEM , but one can see the flow lines are not continuous or exactly parallel.

.

Jim