Winner Announced!! Which of these poor images shows "luster."
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Edit: OK to PM me with your answer if you don't wish to be "On Record in Public."
Several decades ago, a grading instructor gave his beginner's class a similar test as this after a lecture about the mint luster we see on coins. Recently, I read some interesting comments about "luster" that made me realize that many long-time numismatists would flunk this easy test because they are either too smart or don't understand the simple definition of "luster."
TEST:
Question 1: (Optional but very helpful) Define the word "luster."
Question 2: (READ THIS CAREFULLY) Which of the posted images do not have luster?
RULES:
Members who correctly answer this test will be entered into a drawing at the end of this week (Nov. 10th). The prize is a BU Top 100 1921 Infrequent reeded Morgan dollar.
Winner will be notified, and the coin will be shipped at my cost this coming week after I get the address.
I am the sole judge as to the correct answers based on an Advanced Grading Seminar** Lesson.
Good Luck!
** Advanced Grading is where dealers unlearn things they thought they knew. 
Plastic hand lens w/metal pivot
Razor blade
Plastic& rubber pen
Buffalo nickel
Watch battery
Lincoln cent
Comments
I like the intent of your post, but I have to say, you'll get no answers with those pictures.
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There's a fingerprint on the razor blade.
Lance.
@DoubleEagle59 said: "I like the intent of your post, but I have to say, you'll get no answers with those pictures."
LOL, that's the same thing that went through my head when I took the test decades ago. Most of the YN's did just fine. They probably were better listeners, had open minds, and were sucking up knowledge.
At the ripe old age of 30 when I knew all there was to know about coins I missed two!
Give it a try.
I will give it a shot...
Define luster, the way a coins surface reflect light, the more reflection of light, the better the luster.
That said items that do not have luster are: The razor blade and Buffalo nickel.
coin luster: reflective ability of a non-proof field surface.
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Luster - The reflection of light off of a surface.
Which of the items do not have luster? - None
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I have absolutely no idea, but I'll know it when I see it.
Some of those items have reflectivity but that's not the same as luster. I'm sure the unc (and hammered) buff and the lincoln have some degree of luster, how much exactly I can't tell from the pics.
The way light reflects off an object. None of the objects you posted don't have luster.
Luster is the original surface light reflection of metals and plastics surfaces
I’m going with they all have Luster.
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The razor blade, the watch battery and the Lincoln cent.
Luster- reflected light from an objects surface.
Which posted images do not have luster- None
ALL the images have varying degrees of the general definition of the term 'luster'.
"Keep your malarkey filter in good operating order" -Walter Breen
Luster is the sheen present on the surface of an object. The Razor Blade and Penny seem to have lost their luster.
My coins w/luster:
Objects that don't reflect light can't be seen.
I made that up so there's probably a flaw somewhere.
Lance.
I can already tell that I’d be better off not saying much more in this thread.
What about a star like our sun?
Perhaps you might have been one of the members that inspired this thread. I hope you comment further as I know you will have some quality input to help all of us. Nevertheless, there is another "expert" who needs to comment on this childish exercise as it's very quiet around here without him. Crickets.
See? I told you that was weak.
Okay, anything that generates its own light can be seen. A flashlight is lusterful.
Lance.
You made me think of something I haven't thought about in 20 years with your giveaway coin. There was a fairly prominent VAM collector who would stay up and count reeding until he passed out. That always cracked me up back then. I can't remember his name at the moment.
I'll give it a shot cause I need to learn and thanks for the lessons.
Luster is light reflecting off the small grooves created when the coins metal is struck by the press. Can be the same with plastics (except plastic and not metal oriented).
Luster is lost when the small groves wear down.
I think the Lens cover and the penny have lost their luster. Every thing else still has some luster.
I learned that reeding counts are important for coin authentication. The first "published" information I know of was in the Van Allan and George Mallis dollar book. Authenticators in Washington were using them in 1972 and when the first edition of the Seated Liberty half dollar book came out the authors published reeding counts. AFAIK those three places were at the forefront of edge reeding studies. Other than that, a few authors may have occasionally mentioned edge reeding but not anywhere close to the same degree of study.
Edge reeding is not the same as the edge ornamentation seen on earlier issues.
Good information! Yes, most people never think about the reeding for authentication purposes. This guy was collecting VAM's before the "bible" was published and contributed to it. I'll think of his name at some point. He was hilarious. I didn't know the seated liberty half book had that information. Thanks!
The D/S buffalo nickel.
Hoard the keys.
Luster =A soft glow from a partly reflective surface.
They all have 'reflective' surfaces [otherwise they would not be visible] so they all have luster to some degree
so the answer is NONE OF THEM do not have luster
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Oh Rivet....
Hoard the keys.
Luster is the reflected light off a pressed, stamped or otherwise formed, usually metallic (but can be other materials) surface. Wear and/or other treatments can reduce this reflective property. Based on the pictures, I would say none of the items are without luster. Cheers, RickO
Luster is what the human eye sees as a perfect reflection from an objects surface or surface treatment back to our eyes.
Luster can be any grade of light to dark reflection in any original colour as long as it is as perfect and undisturbed as possible.
No luster can be seen on any of your pictured objects.
Does fresh snow have luster? It has a very high albedo.
Lance.
Hmmmmm, this must be a trouble making question.
My little black and white dog has a beautiful lustrous coat of fur. In the sunlight it's just gorgeous and at times I think I can see orange, blues and purples. Oh wait a minute! I'm mixing up my dog from the 60's
To me it's the reflection of light in the grooves (flow lines) of metal pressed under pressure. I've even seen it on keys.
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@lkeigwin said: "Does fresh snow have luster? It has a very high albedo."
In my experience, while living up north, it depends on the position of the sun or moon and where I was standing.
Boston, this is a double negative. your answer means in fact that all have luster! ??????
CascadeChris used to have an avatar .gif that was the perfect example of luster.
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@crazyhounddog said: "Hmmmmm, this must be a trouble making question."
LOL, It can be. Many very experienced folks just parrot information without ever learning the way that information evolved or how it is taught to beginners. Think: "Back to Basics."
Since "Mint Luster" is one of the basic legs on the "grading chair" a truly knowledgeable numismatist
knows what "luster" is and what it looks like! 
PS Clue in this post.
When light reflects off a surface that is covered with tiny imperfections it has a frosty or diffused appearance. That's what I call luster. If the imperfections are arranged in a certain way, such as in rays or concentric circles, I see cartwheeling. I don't think that any of the objects posted "does not have luster" to at least some degree.
I recommend Jason Poe's book "The Art and Science of Grading Coins" for his thorough discussion of luster in its various forms.
Point of order: Starting your class with a quiz probably gives the teacher more information than it does the students.
@TommyType said: "Point of order: Starting your class with a quiz probably gives the teacher more information than it does the students.
"
I'm not the teacher, I'm the parrot. SQUAK! What is "Luster?"
PS You are not entered yet as your post did not qualify.
Care to enter with a better reply? The dollar is a fully lustrous gem!
What? Whining doesn't count? Since when!
My only contribution is this: Being reflective doesn't seem to be the primary requirement. We look at proof coins, (or mirrors), and note that unlike business strike coins, they are NOT lustrous. They are mirrored.
I think KAZ is onto something with his post, about "tiny imperfections" and "diffused appearance". But I don't have a better definition than that.
luster : original and uneven shine after the final stage of production.
images that are lack of luster: Razor blade and Lincoln cent.
Luster is a generic term to describe the reflective property of a coin such as Cartwheel luster.
All could have some luster except the plastic & rubber pen. Metal is the key here, I think since we are talking about coins here. Anything "shiny" I guess could be called luster. This is a coin forum not a shiny object forum.
@TommyType said: "My only contribution is this: Being reflective doesn't seem to be the primary requirement. We look at proof coins, (or mirrors), and note that unlike business strike coins, they are NOT lustrous. They are mirrored. I think KAZ is onto something with his post, about "tiny imperfections" and "diffused appearance."
You are now entered.
If I understand your post, a mirror does not have luster right? What if I toned a mirror proof dark iridescent blue so no "mirror" reflection was present. Can we call the diffused appearance of that coin's surface "luster?"
I was using "mirror" in the common usage, in it's natural state. We could certainly modify a mirror, (or mirrored proof coin), to give it luster. Say, whiz the coin, or sandpaper the mirror.
And I'm going to go out on a limb, and say the rubber pen DOES display some luster. Look at the top surface, and you see a sheen to the photograph. I would contend that could be luster.....(But I share the opinion that the photos are pretty bad).
none of these lackluster items lack luster. - although some are pretty dull!
luster is light reflected off an object
Definition of luster: a gentle sheen or soft glow, especially that of a partly reflective surface.
None lack luster
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@TommyType said: "I was using "mirror" in the common usage, in it's natural state. We could certainly modify a mirror, (or mirrored proof coin), to give it luster. Say, whiz the coin, or sandpaper the mirror. And I'm going to go out on a limb, and say the rubber pen DOES display some luster. Look at the top surface, and you see a sheen to the photograph. I would contend that could be luster.....(But I share the opinion that the photos are pretty bad).
I'm going to say that a wall mirror is not the same as a Proof coin. So while a glass mirror (not in a frame which will change my answer) will reflect luster, a Proof coin will display Proof luster. I've never seen a Proof that did not have luster.
This is really not worth arguing about. But I think you should be prepared to hear that once you reveal YOUR definition of luster, (no matter how good your source)....some of us aren't going to be buyers. We're kind of wandering into a symantics area.
I give you our hosts comment on grading:
https://www.pcgs.com/eyeappeal
"For Mint State and Proof coins, the three factors comprising a coin's "technical grade" are:
1.Number and severity of marks and abrasions
2.Luster, or Reflectivity for Proofs
3.Strike, which is rarely a problem for proofs and strike is expected to be sharp, a weak strike being a deduction in the case of proofs."
Note that according to them, "Luster" applies to MS coins, while "Reflectivity" applies to proof coins.
That's what I've learned, and that makes sense to me.
none of the items do not have luster