What type of material is chalcedony classified as?

Chalcedony is classified as a cryptocrystalline quartz aggregate, which is a key characteristic of this type of stone. It is composed of very fine intergrowths of quartz and moganite, both of which are silica minerals. The term "cryptocrystalline" indicates that the crystals are too small to be seen with the naked eye.

This classification highlights chalcedony's unique structure, which gives it its characteristic translucence and differing color variations. This is also why chalcedony has a smooth, waxy luster and is often used in jewelry and decorative items. Its formation from microcrystalline structures differentiates it from other forms of quartz, such as amethyst or citrine, which are macroscopic in their crystal forms. Understanding this classification is essential in the study of gemstones and their properties.