Carnelian (Semi Precious Stones)

  • Name : Hindi – Rat-Ratua
  • Gem-Group : Chalcedony
  • Crystal Structure : trigonal
  • Composition : Silicon Dioxide , SiO2
  • Hardness : 7
  • Planet : Mars ( mangal) and Sun ( surya)
  • Availability : India and Brazil
  • Specific Gravity : 2.61
  • Refractive Index : 1.53-1.54
  • Double Refraction :  0.004
  • Lustre : Vitreous to waxy
  • Metal : Silver
  • Process : same as that of ruby ( for sun) and like red coral ( for mars)