chalcedony

Chalcedony ( or ) is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic. Chalcedony's standard chemical structure (based on the chemical composition of quartz) is (silicon dioxide).

AI overview

Chalcedony is a type of mineral made from extremely fine mixtures of quartz and moganite, both forms of silicon dioxide, that are so tiny they can't be seen individually with the naked eye. It's composed of the same basic material as regular quartz, but has a different internal structure due to the way these two mineral components are interwoven together.

AI-generated from the Wikipedia summary — may contain errors.

Key facts

Mineral.name: Chalcedony
Mineral.category: Tectosilicate minerals
Mineral.group: Quartz group
Mineral.IMAstatus: Variety of quartz
Mineral.image: Quartz-46809.jpg
Mineral.imagesize: 260px
Mineral.caption: A botryoidal geode specimen from Mexico
Mineral.formula: (silica)
Mineral.molweight: 60 g/mol
Mineral.color: Various
Mineral.habit: Various
Mineral.system: Trigonal (quartz) or monoclinic (moganite)
Mineral.cleavage: Absent
Mineral.fracture: Uneven, splintery, conchoidal
Mineral.mohs: 6–7
Mineral.luster: Waxy, vitreous, dull, greasy, silky
Mineral.streak: White
Mineral.gravity: 2.59–2.61

via Wikipedia infobox

Wikidata facts

Image: Mineraly.sk - chalcedon.jpg

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Commons category: Chalcedony
Commons gallery: Chalcedony
Mohs' hardness: 7.0

Sources (7)

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Article

18 sections

Contents

Varieties
Agate
Carnelian
Chrysoprase
Fire agate
Heliotrope
Moss agate
Chrome chalcedony
Onyx
Chalcedony ice-blue
History
Geochemistry
Structure
Solubility
Solubility of quartz and chalcedony in pure water
See also
References
External links

Chalcedony has a waxy luster, and may be semitransparent or translucent. It can assume a wide range of colors, but those most commonly seen are white to gray, grayish-blue or a shade of brown ranging from pale to nearly black. The color of chalcedony sold commercially is often enhanced by dyeing or heating.