Very shallow hairlines not visible with nakes eyes

[toyonakataro]

I was looking through some raw silver coins in my collection and I occasionally found very shallow/faint hairlines on the surfaces of coins only when I applied 5X magniflying glasses and only when the light hit from certain angle.  Those hairlines are not visible with my naked eyes although I examined them carefully.

If professional graders don't use magnifying glasses and if they only spend 10 seconds grading each coin, I think it's highly possible that they will miss those hairlines, but what do you think? 

[MarkFeld]

2 hours ago, toyonakataro said:

I was looking through some raw silver coins in my collection and I occasionally found very shallow/faint hairlines on the surfaces of coins only when I applied 5X magniflying glasses and only when the light hit from certain angle.  Those hairlines are not visible with my naked eyes although I examined them carefully.

If professional graders don't use magnifying glasses and if they only spend 10 seconds grading each coin, I think it's highly possible that they will miss those hairlines, but what do you think? 

Taro, sometimes graders do use magnifying glasses and they often spend more than 10 seconds grading coins.

Also, some graders might see the hairlines without magnification, even if you can't. On the other hand, in some cases, they probably miss the hairlines, when assigning their grade.

[toyonakataro]

Do you know why they do not always use magnifying glasses?
Too busy or confident enough grading with their naked eyes or both?

[MarkFeld]

In many cases, graders (and other numismatists) can see what they need to see, well enough, without magnification. For example, if the hairlines are minor and only visible with magnification, there is a very good chance they are not really relevant, with respect to the grade that is assigned.

Generally speaking, the higher the grade-range, the more important the hairlines tend to be. And they can be more significant on Proof coins than on business strikes.

[toyonakataro]

8 hours ago, MarkFeld said:

If the hairlines are minor and only visible with magnification, there is a very good chance they are not really relevant, with respect to the grade that is assigned.

Generally speaking, the higher the grade-range, the more important the hairlines tend to be.

That makes scence a lot to me.  Thank you for the clarification.