Is Onyx Natural or Manmade?

“Is onyx natural or manmade?”
Onyx is natural, and chemically speaking it is a cryptocrystalline  type of quartz.  It is normally black in colour, but it can be found in a plethora of different colours.  The layers or different colours which are present in onyx make it very sought after for carving.  This is because it is easy to use the different layers to build up one coloured image with another as a background.  It is a semi precious stone, but is readily available so its value is not very high.  It is used widely in making necklaces, bracelets and pendants, but is also widely used for making ornamental objects and statues.