I've been surfing around this site for the last couple of days and I've seen an awful lot of threads discussing Counterfeit Morgans. How can you tell by looking --- wether or not it is a legitimate coin
a lot of it, I imagine, comes from seeing a LOT of genuine examples and a lot of experience. The more coins you can see, the better. Pretty soon, you start to know how a coin should look, in all stages of circulation and mint states. Then there is the tells - casting lines, bubbles, sandy fields, etc. There are also tells for alterations and so forth. So the only answer that I, personally, can give you is that the opinions often come from people have given the subject significant research or have seen enough to know when it looks wrong.
You can't always tell by looking. Some counterfeits are so good that they have fooled even the experts that examined them in person - for over 100 yrs. Others are so poorly made that even a beginner can see they are fakes. What rick said is very true - many counterfeits are well known. Some of them have a little mark here, and indentation there - and so on. And if study and do the research - you come to be familiar with them. Others must be weighed & measured - as well as looked at to confirm authenticity. Coin collecting is like any other trade - if you spend 40 or 50 yrs doing it and striving to learn as much as possible every single day - pretty soon you get good at it
