The hardie is used in combination with a mosaic hammer to cut tesserae.  

When you don't have a log to mount your hardie in, or when you need to easily transport your hardie, this tabletop version is an excellent choice. Using the same materials as our standard steel tipped hardie, this version is mounted on an 8 lb plate for stability and durability.

In addition, this version includes a nylon insert into the base.  After you have cut a piece of material, you may need to do some "nibbling" to modify the shape.  With a log-mounted hardie, you place the material on the wooden log and then when shaping with the hammer, if you accidently strike the log (you will!) there is no damage to the hammer tip.  The nylon insert serves the same purpose.

Steel hardies are suitable for cutting glass and stone.