Difference between revisions of "Smoky quartz"
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| − | [[File:Smoky Quartz-MFA.jpg|thumb| | + | [[File:Smoky Quartz-MFA.jpg|thumb|Janus necklace<br>MFA# 2007.422]] |
[[File:Smoky.Quartz.jpg|thumb|Smoky quartz]] | [[File:Smoky.Quartz.jpg|thumb|Smoky quartz]] | ||
== Description == | == Description == | ||
| Line 12: | Line 12: | ||
== Physical and Chemical Properties == | == Physical and Chemical Properties == | ||
| − | Trigonal crystal system | + | * Trigonal crystal system |
| − | + | * Low birefringence (0.009) | |
| − | Fracture = conchoidal | + | * Low thermal expansion |
| − | + | * Fracture = conchoidal | |
| − | Heat-treatment can bleach the stone and may turn it yellow. | + | * Luster = vitreous to greasy |
| + | * Streak = white | ||
| + | * Fluorescence = generally inert | ||
| + | * Pleochroism = very weak with different tones of body color | ||
| + | * Can be piezoeletric and/or triboluminescent | ||
| + | * Heat-treatment can bleach the stone and may turn it yellow. | ||
{| class="wikitable" | {| class="wikitable" | ||
| Line 27: | Line 32: | ||
|- | |- | ||
! scope="row"| Density | ! scope="row"| Density | ||
| − | | 2.65 | + | | 2.65 g/ml |
|- | |- | ||
! scope="row"| Refractive Index | ! scope="row"| Refractive Index | ||
| − | | 1. | + | | 1.544; 1.553 |
|} | |} | ||
| Line 39: | Line 44: | ||
==Resources and Citations== | ==Resources and Citations== | ||
* Mineralogy Database: [http://www.webmineral.com/data/Quartz.shtml Quartz] | * Mineralogy Database: [http://www.webmineral.com/data/Quartz.shtml Quartz] | ||
| − | * | + | * Gem Identification Lab Manual, Gemological Institute of America, 2016. |
| − | |||
* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982 | * Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982 | ||
| − | |||
* ''Encyclopedia Britannica'', http://www.britannica.com Comment: "smoky quartz." Accessed: 21 Jan. 2005 . | * ''Encyclopedia Britannica'', http://www.britannica.com Comment: "smoky quartz." Accessed: 21 Jan. 2005 . | ||
| − | |||
* C.W.Chesterman, K.E.Lowe, ''Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf, New York, 1979 | * C.W.Chesterman, K.E.Lowe, ''Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf, New York, 1979 | ||
| − | + | * Wikipedia: [https://en.wikipedia.org/wiki/Smoky_quartz Smoky quartz] (Accessed Sept. 14, 2005 and Dec 2022) | |
| − | * Wikipedia: | ||
| − | |||
* Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997 | * Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997 | ||
Latest revision as of 11:38, 26 December 2022
Description
A transparent dark gray or brown Quartz, also called cairngorm. Smoky quartz is found in Switzerland, Scotland (Mt. Cairngorm), Russia, Iran, Brazil, Sri Lanka and the U.S.(Colorado, California). It is sometimes used as a Gemstone. Most early uses of the stone date from Hellenistic times or later; one earlier example was found in Iran c 3250 BCE (Odgen 1982).
Synonyms and Related Terms
smokey quartz; cairngorm; Cairngorm stone; Rauchquarz (Deut.); quartz fumé (Fr.); quartzo fumado (Port.); rookkwarts (Ned.)
Physical and Chemical Properties
- Trigonal crystal system
- Low birefringence (0.009)
- Low thermal expansion
- Fracture = conchoidal
- Luster = vitreous to greasy
- Streak = white
- Fluorescence = generally inert
- Pleochroism = very weak with different tones of body color
- Can be piezoeletric and/or triboluminescent
- Heat-treatment can bleach the stone and may turn it yellow.
| Composition | SiO2 |
|---|---|
| Mohs Hardness | 7.0 |
| Density | 2.65 g/ml |
| Refractive Index | 1.544; 1.553 |
Comparisons
Properties of Common Gemstones
Resources and Citations
- Mineralogy Database: Quartz
- Gem Identification Lab Manual, Gemological Institute of America, 2016.
- Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
- Encyclopedia Britannica, http://www.britannica.com Comment: "smoky quartz." Accessed: 21 Jan. 2005 .
- C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
- Wikipedia: Smoky quartz (Accessed Sept. 14, 2005 and Dec 2022)
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997