Found this link and thought it had some value. It shows (with pictures) how to distinguish counterfeit Sharpstone Grinders and Pollen Presses from AUTHENTIC ones. The Other Side Vapes: SharpStone® Grinder & Pollen Press Authenticity Guide
Here's another thread about this problem: http://forum.grasscity.com/toking-tools/826722-counterfeit-sharpstone-grinders-presses.html We've done some more work since the last post, and eBay looks to be about completely clear on fake sharpstone grinders and presses!