1906-S Liberty Head Double Eagle 20 Dollar Gold Coins ?

Not from an image and especially not from one that size.

To answer your question about how do you tell the difference its about luster and fine details. AU has a very noticable luster and all the "knobs" will be intact and you will be able to see the finer details on the obverse and reverse side.

I didnt even notice that. In that case my grading might be a little off. Maybe MS54 is more of the grade you are looking for.

Anyone who offers a firm opinion based on these images is misleading you. They are too small for a comfortable evaluation of either grade or authenticity.

Some things tend to indicate that it's authentic. It's a high-mintage coin, and unsurprising to find one in your part of the world. This is encouraging. The coin has been brushed - you can see it best in the obverse images. This means it cannot receive an "original" grade, but must be considered "cleaned" at a substantial reduction in value. This is a hint in favor of authenticity as well; why clean a counterfeit?

But none of that offers any certainty. The coin needs to be personally inspected by someone with the expertise to properly evaluate it, and that is the only way to ever be sure. It's quite possible for a counterfeit to be undetectable in the finest of photographs.

If real, the brushing has destroyed any numismatic value, leaving the coin's worth tied strictly to the price of gold. That brushing could have cost US$2000-3000 in value. Below I'll link a good site to learn grading standards for this coin, with the understanding that the brushing means the best grade it's eligible for is "Uncirculated Details." Surface originality is prized in the numismatic world.

http://www.pcgs.com/photograde/#/20Lib/Grades

thanks for the information guys! I can e-mail the photos for a larger view if you guys are willing to help me.

Absolutely. We prohibit new members from communication outside the forum for their own protection, but I can reach out to you via your registration email. I will be happy to get your larger images up here.

I am skeptical about the authenticity. I compared your coin with the one in the link D0ubl3Eagle provided and I agree that the date doesn't look right. There are also some features that don't look the same but that all could be in the strike. I'm not an expert when it comes to these so don't take my word for it, that's just my opinion.One thing for sure is that it has been harshly cleaned.