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Explain Luster to the new but dedicated collector.
MGLICKER
Posts: 7,995 ✭✭✭
I invite TDN to go first.
0
MGLICKER
Posts: 7,995 ✭✭✭
MGLICKER
Posts: 7,995 ✭✭✭
MGLICKER
Posts: 7,995 ✭✭✭
MGLICKER
Posts: 7,995 ✭✭✭
Comments
reason I say that is I'm a nickel guy and there are certain years where
better quality FULL STRUCK Nickels are penalized because of there lack
of LUSTER, as a coin with blazing luster may garner a MS66 grade, if kept
in your pocket for a half hour may only get a VF20 grade !!!!
Steve
Steve
<< <i>Luster is over rated sometimes, however it is a good thing sometimes. Reason I say that is I'm a nickel guy and there are certain years where better quality FULL STRUCK Nickels are penalized because of there lack of LUSTER >>
This is true for Buffalo Nickels as well so I agree with Steve.
Great transactions with oih82w8, JasonGaming, Moose1913.
Something to the effect of "I know it when I see it"
Same kind of thing....
Happy, humble, honored and proud recipient of the “You Suck” award 10/22/2014
If the surfaces of a coin are smooth as glass, parallel rays of light coming at the coin will remain parallel when they bounce off the coin, and will not lose much intensity by the time they hit your eye. That's a fully lustrous, proof-like coin.
If the surfaces are roughed up and worn from circulation, the reflected rays of light bounce off in many random directions, and the coin does not have the much reflective flash. That's a circulated coin with no luster.
Now consider "cartwheel luster", which is what you see on a mint state coin that is not "smooth as glass", but instead has many "radial flow lines". (Radial flow lines are microscopic ridges of metal that flow outwards from the center of the coin, and are the result of the outward expansion of metal filling in a pattern of wear on a used die.) Although the coin is not smooth, you'll get a lot of light reflected back at certain angles, because the flow lines are aligned with each other, and more or less reflect light in the same way, at the same angles.) That's a fully lustrous non-PL coin.
Naturally, a coin that has seen little wear may still have traces of the original luster remaining, because some of the original surface remains intact.
Doggedly collecting coins of the Central American Republic.
Visit the Society of US Pattern Collectors at USPatterns.com.
When a coin is struck metal is pushed out from the center towards the edges and these lines of the metal flow reflect the light and give the viewer the sheen known as luster.
A coin without luster is basically a flat surface and doesn't shine.
<< <i>Hell, explain it to the experienced collector. >>
A Morgan Dollar Graded Mint State 68 (MS-68) that exhibits
the cartwheel effect or luster. Photo courtesy of Teletrade Coin Auctions,
Definition:
Luster on a coin's surface is the sheen or reflective qualities that are produced during the minting process. When a coin is struck,
metal flows from the center of the coin towards the outer edge. This process produces microscopic *striations (very tiny parallel grooves)
that reflect light back to the viewer in a unique crossing pattern. As the coin is tilted under a light, this crossing pattern will spin around the coin.
This is known as the cartwheel effect.
Official A.N.A. Definition: Luster, or mint bloom or frost, is one of the most important aspects of grading in the Mint State category.
All other things being equal, a coin with rich, deep mint luster is a better candidate for a higher grade than is one with a dull or lifeless luster.
One rule does not fit all; luster can vary from type to type, and examination of a wide selection of coins in the marketplace
is the best way to gain expertise in this vital feature.
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Liberty: Parent of Science & Industry
Great transactions with oih82w8, JasonGaming, Moose1913.
<< <i>Luster is all about optics and reflectivity.
If the surfaces of a coin are smooth as glass, parallel rays of light coming at the coin will remain parallel when they bounce off the coin, and will not lose much intensity by the time they hit your eye. That's a fully lustrous, proof-like coin.
If the surfaces are roughed up and worn from circulation, the reflected rays of light bounce off in many random directions, and the coin does not have the much reflective flash. That's a circulated coin with no luster.
Now consider "cartwheel luster", which is what you see on a mint state coin that is not "smooth as glass", but instead has many "radial flow lines". (Radial flow lines are microscopic ridges of metal that flow outwards from the center of the coin, and are the result of the outward expansion of metal filling in a pattern of wear on a used die.) Although the coin is not smooth, you'll get a lot of light reflected back at certain angles, because the flow lines are aligned with each other, and more or less reflect light in the same way, at the same angles.) That's a fully lustrous non-PL coin.
Naturally, a coin that has seen little wear may still have traces of the original luster remaining, because some of the original surface remains intact.
-------------------------
Andy Lustig >>
Well Said
www.brunkauctions.com
Leo
The more qualities observed in a coin, the more desirable that coin becomes!
My Jefferson Nickel Collection
<< <i>Well, this one doesn't have "radial flow lines" or "microscopic striations" that produce luster. But yet, this coin has one of the earliest die state strikes I have come across in 23+ years. How could this happen. I've read here that the first few strikes from fresh new dies will not be lustrous until these "radial flow lines" or "microscopic striations" have formed. My coin does have a subtle, soft level of luster, more akin to a satin appearance. This coin will stay with me and beyond because no-one, to my knowledge, understands it's rare state of quality.
Leo >>
That sir is one very nice nickel and shows how hard it is to show and tell what coin luster is. I would also ask " would a coin collector be considered a coin luster?"
Latin American Collection
Try PCGS Photograde for some pictures.
edited to add: Goldbully's pointed mention of striations goes to the core of the technical issue. Die quality, planchet quality, striking pressure etc. all contribute to the metal flow and the resultant optical effects. Looks like another world under an SEM. Pictures abound.
I expect CaptHenway to chime in, but the science takes a back seat to perception when you see it often enough in hand. White and bright can be original or semi-burnt from waay too much acid dip. As the striations are shallowed by being eaten away, you lose the glow before the flash.
If one picture is worth a thousand words, look at the HA archives for anything anything anything whatsoever. You'll learn much more by experiencing it visusally than anything posted here.
<< <i>It's like "Porn" you'll know it when you see it.
Not really, some people think nude photography is porn, when it really isn't.
And some people think just because a coin is silver and bright, it has luster, which
it may not.
Maybe a wizzed coin is like when musicians would try to sneak things buy sensors ?
As a closing note for an example of the 3rd level, when ever I look at this coin below I need to lace up my shoes very tight before I look...
AB
a) spot on.
b) something every collector should understand before ever spending a penny in this hobby.
<< <i>Well, this one doesn't have "radial flow lines" or "microscopic striations" that produce luster. But yet, this coin has one of the earliest die state strikes I have come across in 23+ years. How could this happen. I've read here that the first few strikes from fresh new dies will not be lustrous until these "radial flow lines" or "microscopic striations" have formed. My coin does have a subtle, soft level of luster, more akin to a satin appearance. This coin will stay with me and beyond because no-one, to my knowledge, understands it's rare state of quality.
>>
no expert here leo by any means
but your coin i would guess is a set-up piece on fresh dies
as an ex-machinist...the 1st pieces i made always had extra care applied...then once proved...i'd kick it into high gear
so yeah your coin to me was when the coiner was setting up for production run
luster
alot of luster can be attributed to this issue i mention here
hot dies running at full speed
produce a "heat generated luster"
where as
slow speed and cold dies won't
dcar could verify this as surely this contributes to one aspect of luster's birth
double post crap
Consider 83-84-85 O-Mints from rusted dies, some of the same dates also having some great DMPLs and then satiny later O-mints. Superbly frosty 80-CC $1 soft over the ear. And on and on and on.
Proof ASE's are not subjected to the same laser-verified gazillion-to-the inch tolerances as jet engine parts.
There are scads of SEM photos of this phenomenon starting with ANACS research in the early 80's. Proofs included.
If FredWeinberg, CaptHenway or dcarr chime in, all the better, but again, look at pictures or, best, in-hand. Waste an hour or two of some major auctioneer's box-watcher's seat time and go through boxes fast. You're required to register, but need not buy anything.
And PCGS PhotoGrade is FREE