what is the name onyx
Onyx is the birthstone for Leos and the anniversary gemstone for the 7th year of marriage. Black Onyx is the anniversary gemstone for the 10th year of marriage. Onyx is a variety of the microcrystalline quartz, called chalcedony. The name â chalcedony â comes from Calcedon or Calchedon, an ancient port on the Sea of Marmara in Asia Minor.