There are many high quality counterfeits that are out in the market these recent years. You might want to post it in the specialized section of the Russian coin forum in the following homepage: http://www.coinpeople.com There are many experts regarding about Russian coins and I am in there too. Welcome to cointalk by the way.
As we Brits would say, it's as fake as a nine bob (9/-) note. definitely not the genuine item. If you are thinking of buying it....avoid like the plague. If it's too late and you've already done so, i hope that you didn't pay more than $5 for the priviledge. Now.....if you are trying to sell it as being a genuine coin from 1738....well you've got a real job of work on your hands. Ian
lenit2, it just suggests to me that it's a counterfeit. The text font on above the Empress Anna is completely wrong, as well as the wearing. It might be because you used a scanner to scan it but I still think something is wrong. Do a favor and sign up at coinpeople.com
I have little knowledge of world coins, however I agree that it is most likely counterfeits. There are raised lumps of metal which isn't a good sign.
lenit, here is a page that has three photos of similar,authentic Annas so you can compare for yourself. http://images.google.com/imgres?img.../images?q=anna+rouble&svnum=10&hl=en&lr=&sa=N