Black agate slither on black cord.
Agate is a banded form of finely-grained, microcrystalline Quartz. The lovely color patterns and banding make this translucent gemstone very unique. Agates can have many distinctive styles and patterns, but each Agate is unique in its own habit, with no two Agates being the same.
Most agate has unimpressive colors and patterns. However, agate is a porous material that readily accepts dye. Most of the spectacularly colored agates sold in the gemstone trade have been dyed.