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chalcedony

Microcrystalline varieties of silica, may contain moganite as well

Instance of: mineral variety
Subclass of: quartz
1
Sources
1.hedendaagsesieraden.nl/2025/09/07/chalcedoon/
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Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Chalcedony is an aggregate of cryptocrystalline or microcrystalline silica, or in simpler terms, a mass of individual silica crystals that are too small to be seen without magnification. It is composed primarily of quartz, with minor amounts of intergrown moganite. These are both silica minerals with a chemical composition of SiO2, but they differ in that quartz has a more symmetrical crystal structure (trigonal) than moganite (monoclinic). Mineralogically speaking, the quartz and moganite crystals in chalcedony must grow in parallel chains, called "fibers." However, the term chalcedony may more broadly refer to any microcrystalline or cryptocrystalline silica, fibrous or not.

Overview

All data

38 statements · 18% with external sources · numbers in brackets are citations

Crystal system: trigonal crystal system
Streak color: white
Mohs' hardness: 7
Different from: Chalcedon

On other databases

33 identifiers linking chalcedony across the web's reference databases

Data quality

statements

18%

externally sourced

Source last edited September 14, 2026. AIDb refreshes this page daily.

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AIDb. (2026). chalcedony (Q170448). Retrieved from https://aidb.si/e/chalcedony-Q170448