Chalcedony
| ID | 237 | |
|---|---|---|
| Mineral | Chalcedony | |
| Location | Oregon - United States of America | |
| Fluorescence | LW-UV: check SW-UV: check |
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| Mindat.org |
View Chalcedony information at mindat.org |
|
Mindat data
| ID | 960 |
|---|---|
| Long ID | 1:1:960:9 |
| IMA Status |
0 1 |
| Variety of | 3337 |
| Entry type | 2 |
| Description | Depending on the context, the term "chalcedony" has different meanings. 1. A more general term for all varieties of quartz that are made of microscopic or submicroscopic crystals, the so-called microcrystalline varieties of quartz. Examples are the ... |
| Other Occurrences | Very common. As nodules, vein fillings, crusts in volcanic rocks. As sinter-like crusts in low- to medium temperature hydrothermal veins. Main constituent in silica-rich marine sedimentary rocks. As nodular concretions and layers in limestones and marls. As a metasomatic replacement in limestones and marls ("replacement chert"). As cement in sandstones. Replacing other minerals in pseudomorphoses. As a fossilizing material (petrified wood, coral agate). |
| Diapheny | Translucent |
| Tenacity | brittle |
| Colour | colorless, white, gray, blue, any color due to embedded minerals, multicolored specimen not uncommon. |
| Hardness (min) | 7.0 |
| Hardness (max) | 7.0 |
| Lustre | Vitreous |
| About the name | Mentioned by Agricola (1546) of a stone named for the town of Chalcedon, now called Kadıköy, and is a district within the city of Istanbul, Turkey. |
| Streak | White |
| Crystal System | Trigonal |
| Cleavage Type | None Observed |
| Fracture type | Conchoidal,Sub-Conchoidal |
| Twinning | Quartz crystallites in the chalcedony fibers are polysynthetically twinned by the Brazil law (left- and right-handed domains). |
| UV | None in a pure specimen, however, green fluorescence in short-wave UV light is very common at many localities. |
| Comment Luster | vitreous when polished, fractured surfaces have a dull or waxy luster |
Details
Price: € 5
Dimensions: Not registered
Weight: 54 g
Visibile in overview:
Notes:
| Symbol | Element | |
|---|---|---|
| O | Oxygen | |
| Si | Silicium |