Agate is one of the most important gemstones because of the extent it has been used in jewelry in many countries since antiquity.
Agates can be categorized as banded and those that are not banded.
Some gemstones that have been used, named and marketed as agate are indeed not real agates and many of them are carnelian, onyx or jasper.
Hardness of agates is usually 7 or sometimes a bit harder around 7.5.
Agate is sometimes used by artists to create bowls, cups or other ornamental objects.
One of the most amazing phenomena about agate is the presence of water in large amounts in some agates and in some cases it is so prominent that the water can be clearly seen inside the agate when moving some agate stone in different directions. The water inside those agates is the result of the water getting trapped inside of the stone during formation of it.