Blue Chalcedony: A Tranquil Oasis of Healing The magnificent gemstone known as Blue Chalcedony has calming, gentle blue tones. The stone belongs to the quartz family and is composed of silicate minerals. Minerals called silicates are made up of silicon and oxygen.The two primary categories of quartz are microcrystalline and macrocrystalline. Amethyst and Clear Quartz are two examples of macrocrystalline quartz, which contains well-formed crystals big enough to be seen with the unaided eye.