I have different kinds and the main 3 I have on hand I use for different reasons. 

I adore my Ruby Stone nail file. It is a crystal nail file made up of the same stuff that rubies are and also my very first introduction into the wonderful world of crystal nail files. They are a lot better for your natural nails and don’t tear and break as easily as they would with regular cheap emery boards. Not to mention it is very eco friendly since they last for years and you can sanitize them. The Ruby Stone however does a fatal flaw. The grit on it does not file very much. Even the edge which is a much better grit doesn’t speed things up. I have had this file since early summer, and my nails have been better for it since the purchase it’s just when I went to do some drastic shaping of my nails it took forever. But what I love about it is that you can use the top edge for a cuticle pusher and makes my nails feel sharp, smooth, and strong and for that it will always be my go to nail file. $3.49 at Sally’s! 

I now have a different crystal nail file I got at H.E.B it is from LaVague. Apparently they do mostly tweezers. It is a simple double sided file that has a sharp edge much like a metal file does. It is a little thick but I have gotten very use to that thanks to my Ruby Stone however, this makes the top useless to clean under the nails with. It is also a lot sharper than the other. This is the reason I bought it. So that when I go to do some serious filing away to shape the nail I can do it in no time and this works wonders for that. But I do not like the way the nails feel afterward so I just take my other nail file to smooth up the edges and it’s good to go. $7.99 at H.E.B (yeah I know kinda expensive) 

Lastly I have a cheap metal file. The only use it gets is for that top that cleans under the nails and also as my scratcher for when my nails are wet, lol. Just get a dollar one to do that with. Do not ever file with a metal file! It is super bad for your nails especially if you have a habit of doing a back and forth motion. It has the power to tear and break even the strongest of nails.

So there you have it! One for touch ups and health, one for serious filing, and another to clean. 

I really do highly recommend the Ruby Stone if nothing else. Especially if your just looking for something to smooth out your nail, it is the perfect one trust me nothing else has made my nails smoother than this.