Agate Gemstone is one of my favorite stones to use in my classic gallery design in my jewelry line.  Agate can have so much character and pattern, which is what I love.  They have a 6 1/2 - 7 on the  Mohs' hardness scale and takes a great polish.  They are usually enhanced by dyeing and heating.

 There is a modern unique process where a design is painted on them with an alkaline metal and then fired.  This design is called DZI, originated in ancient Tibet.  I believe I have become somewhat obsessed with these unique gemstones, wanting them in all colors with all kinds of designs.  I like to do a classic gallery design with a tribal style with the agate gemstones, especially faceted ones. There are many websites and books just for agates for gemlovers to enjoy.