Mineral
Chalcedony
Silicate Minerals
Chalcedony is an aggregate of cryptocrystalline or microcrystalline silica, a mass of individual silica crystals too small to be seen without magnification, composed primarily of quartz with minor amounts of intergrown moganite. It has a waxy luster and may be semitransparent or translucent, and it takes a wide range of colors, most often white to gray, grayish-blue or brown. In this atlas it is the mineral species named for the many banded and colored silica gemstones, so the gemstones that record chalcedony as their species can be grouped and compared on one entity.
Chalcedony is an aggregate of cryptocrystalline or microcrystalline silica, a mass of individual silica crystals too small to be seen without magnification, composed primarily of quartz with minor amounts of intergrown moganite. It has a waxy luster and may be semitransparent or translucent, and it takes a wide range of colors, most often white to gray, grayish-blue or brown. In this atlas it is the mineral species named for the many banded and colored silica gemstones, so the gemstones that record chalcedony as their species can be grouped and compared on one entity.
Facts
Chemical Formula Chemical Formula Hardness (Mohs)Commonly cited range is 6 to 7 on the Mohs scale; 6.5, the midpoint, is used here. Hardness (Mohs)Commonly cited range is 6 to 7 on the Mohs scale; 6.5, the midpoint, is used here. Classification
Strunz Class Strunz Class Connections
Caused By
Source EBSCO Research Starters: Hydrothermal solutions and mineralization
In Discipline
In the Other Atlases
Mineral Species Of
Also in Divinity Atlas: of this mineral species.
Also in Divinity Atlas: of this mineral species.
Also in Divinity Atlas: of this mineral species.
Also in Divinity Atlas: of this mineral species.
Also in Divinity Atlas: of this mineral species.
Sources
1. Chalcedony (Wikipedia)
Wikimedia FoundationChalcedony, lead paragraph
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.
Chalcedony, article text
It is composed primarily of quartz, with minor amounts of intergrown moganite.
View the Source 2. Chalcedony (Wikipedia)
Article body
Many semi-precious gemstones are in fact forms of chalcedony.
Article body, gemstone
Many semi-precious gemstones are in fact forms of chalcedony.
View the Source3. minerals.net: Chalcedony
minerals.netColor field
White, blue, red, green, yellow, orange, brown, pink, purple, gray, black, colorless, and multicolored. Often banded in many different color combinations, and a few rarer forms are iridescent.
Luster field
Vitreous, waxy, or dull
View the Source Agate (Wikipedia)
Caused By: Volcanism, Nodular agateQuote, Caused By: Volcanism, Nodular agate
Agates are most commonly found as nodules within volcanic rocks.
EBSCO Research Starters: Hydrothermal solutions and mineralization
EBSCO Research StartersCaused By: Hydrothermal Mineral Deposition, Hydrothermal deposit types and gangue mineralsQuote, Caused By: Hydrothermal Mineral Deposition, Hydrothermal deposit types and gangue minerals
Gangue minerals include barite, fluorite, chalcedony, opal, calcite, and aragonite.
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