You can try a local Ace or Lowes. Many of each cut glass.
This is not designed for cutting anything but glass.
YES! Make sure and cut the front of the mirror (not the silver side). If trying to cut a very large mirror, it is probably 1/4" thick. Keep in mind that is the max thickness this cutter can handle (for a DIYer). Cutting 1/4" thick material is not as easy as thinner glass or mirror if you are cutting for the first time. If this is the case, make sure and watch some Videos on the internet, AND buy some thinner glass or use some scrap to practice making a couple of cuts. Understanding the sound the cutter makes when you are doing it right is VERY important. Keep constant pressure, don't press down really hard, use the oil, make sure the mirror has been thoroughly cleaned BEFORE applying the oil or starting the cut. If you will be discarding part of the mirror once you cut it, personally I would go ahead and cut off a smaller section to start so you can essentially practice on the same material BEFORE actually cutting it at the final dimension. Just don't try and cut off anything less than a couple of inches as practice, because you will be asking for trouble. The bigger the piece you cut off the easier it is, well kind of. Cheers!
You could try it. Im not sure if it would work though. I usually use a piece of string and denatured alcohol to cut bottles. You take the string and soak it in denatured alcohol or acetone. wrap the string around the bottle a few times where you want to cut the glass. Then light the string on fire. while its lit hold the bottle at the mouth and twist it back and forth until you see the string begin to burn. Then plunge the bottle into a bucket of ice cold water. This will shock the class and it will break of at the point where the string was for a clean cut. Sounds crazy but it really does work well.
Tool needed to cut up to 1/2" glass
I wouldn't advise cutting a window that's in place (installed). The chances of shattering the window are high.
Yes you can use the Glass-Cutting Tool Kit for cutting glass mosaic.
This glass cutting tool kit is meant to be used per the instructions on the package. Thank you--
This product is intended for glass. Thank you --
I've used this type of cutter for Mirrors up to 3/8". It was not easy. I took my time to score the glass deeply enough for a clean break.