Difference between revisions of "Carnelian"

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== Physical and Chemical Properties ==
 
== Physical and Chemical Properties ==
  
* Trigonal crystal system 
+
* No visible crystals
* Fracture = conchoidal
+
* Fracture = conchoidal, uneven, splintery
* Luster = vitreous to waxy. 
+
* Luster = waxy to vitreous
* Streak = white.
+
* Streak = white
 +
* Fluorescence = generally inert
 +
* Pleochroism = absent
  
 
{| class="wikitable"
 
{| class="wikitable"
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|-
 
|-
 
! scope="row"| Mohs Hardness
 
! scope="row"| Mohs Hardness
| 7.0
+
| 6.5-7.0
 
|-
 
|-
 
! scope="row"| Density
 
! scope="row"| Density
| 2.6 g/ml
+
| 2.59-2.61 g/ml
 +
|-
 +
! scope="row"| Refractive index
 +
| 1.535 - 1.539
 +
|-
 +
! scope="row"| Birefringence
 +
| undetectable to 0.04
 
|}
 
|}
  
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* Mineralogy Database: [http://www.webmineral.com/data/Quartz.shtml Quartz]
 
* Mineralogy Database: [http://www.webmineral.com/data/Quartz.shtml Quartz]
 
* ''Encyclopedia Britannica'', http://www.britannica.com  Comment: "carnelian." Accessed 14 Sept. 2001 .
 
* ''Encyclopedia Britannica'', http://www.britannica.com  Comment: "carnelian." Accessed 14 Sept. 2001 .
 
+
* Gem Identification Lab Manual, Gemological Institute of America, 2016.
 
* 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/Carnelian Carnelian] (Accessed Sept. 14, 2005 and Dec 2022)
* Wikipedia: http://en.wikipedia.org/wiki/Carnelian (Accessed Sept. 14, 2005)
 
  
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Revision as of 11:03, 19 December 2022

Lentoid seal
MFA# 1971.173

Description

Carnelian amulets
MFA# 35.1500

A pale orange-red to deep red translucent stone that is a variety of Chalcedony. Carnelian was mined or gathered as an ornamental stone since at least 3000 BCE. It is found in Egypt, India and areas of Europe as water-worn pebbles. Carnelian was popular for amulets and scarabs and is still used as gemstones.

Carnelian cabochon

Synonyms and Related Terms

sard; cornelian; chalcedony; Karneol (Deut., Pol.); cornaline (Fr.); cornalina (Esp., Port.)

Physical and Chemical Properties

  • No visible crystals
  • Fracture = conchoidal, uneven, splintery
  • Luster = waxy to vitreous
  • Streak = white
  • Fluorescence = generally inert
  • Pleochroism = absent
Composition SiO2
Mohs Hardness 6.5-7.0
Density 2.59-2.61 g/ml
Refractive index 1.535 - 1.539
Birefringence undetectable to 0.04

Comparisons

Properties of Common Gemstones

Resources and Citations

  • Mineralogy Database: Quartz
  • Encyclopedia Britannica, http://www.britannica.com Comment: "carnelian." Accessed 14 Sept. 2001 .
  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
  • Wikipedia: Carnelian (Accessed Sept. 14, 2005 and Dec 2022)

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