A cryptocrystalline form of silica (quartz), encompassing many varieties based on color and pattern. Generally, Chalcedony is a nurturing stone promoting goodwill, harmony, and emotional balance.
White, Grey, Blue, Pink, Brown, Yellow, Red, Green, (Agate: banded, Jasper: opaque, patterned)
Chalcedony is classified as a tectosilicate minerals, quartz group mineral which typically crystallizes in the trigonal (quartz) or monoclinic (moganite) system. Its chemical formula is SiO2.