Difference between revisions of "Chrysoprase"

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[[File:1998.400a-b-SC8651.jpg|thumb|Decanter<br>MFA# 1998.400]]
 
[[File:1998.400a-b-SC8651.jpg|thumb|Decanter<br>MFA# 1998.400]]
 
== Description ==
 
== Description ==
 
+
[[File:SC184961.jpg|thumb|Arts & Crafts brooch<br>MFA# 2008.264]]
 
A translucent, apple-green stone composed of microcrystalline [[quartz]].  Chrysoprase is a variety of [[chalcedony]] that contains small amounts of hydrated nickel silicate.  The gemstone has occasionally been found in Egyptian, Greek, and Roman jewelry.  Chrysoprase was also valued for mural decorations.
 
A translucent, apple-green stone composed of microcrystalline [[quartz]].  Chrysoprase is a variety of [[chalcedony]] that contains small amounts of hydrated nickel silicate.  The gemstone has occasionally been found in Egyptian, Greek, and Roman jewelry.  Chrysoprase was also valued for mural decorations.
  
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== Physical and Chemical Properties ==
 
== Physical and Chemical Properties ==
  
Fracture = conchoidalLuster = vitreous to waxy.  Streak = white.
+
* No visible crystals
 +
* Fracture = conchoidal, granular
 +
* Luster = waxy to greasy
 +
* Streak = white
 +
* Fluorescence = generally inert
 +
* Pleochroism = absent
  
 
{| class="wikitable"
 
{| class="wikitable"
 +
|-
 +
! scope="row"| Composition
 +
| SiO2
 
|-
 
|-
 
! scope="row"| Mohs Hardness
 
! scope="row"| Mohs Hardness
| 7.0
+
| 6.0-7.0
 
|-
 
|-
 
! scope="row"| Density
 
! scope="row"| Density
| 2.6
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| 2.65-2.91 g/ml
 +
|-
 +
! scope="row"| Refractive index
 +
| 1.535 - 1.539
 +
|-
 +
! scope="row"| Birefringence
 +
| 0.004 - 0.009
 
|}
 
|}
  
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==Resources and Citations==
 
==Resources and Citations==
 
+
* Gem Identification Lab Manual, Gemological Institute of America, 2016.
 
* Mineralogy Database: [http://www.webmineral.com/data/Quartz.shtml Quartz]
 
* Mineralogy Database: [http://www.webmineral.com/data/Quartz.shtml Quartz]
 
 
* 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
 
 
* A.Lucas, J.R.Harris, ''Ancient Egyptian Materials and Industries'', Edward Arnold Publishers Ltd., London, 4th edition, 1962
 
* A.Lucas, J.R.Harris, ''Ancient Egyptian Materials and Industries'', Edward Arnold Publishers Ltd., London, 4th edition, 1962
 
 
* 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
 
 
* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 647
 
* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 647
 
+
* Wikipedia: [https://en.wikipedia.org/wiki/Chrysoprase Chrysoprase] Accessed Dec 2022.
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Latest revision as of 12:14, 19 December 2022

Decanter
MFA# 1998.400

Description

Arts & Crafts brooch
MFA# 2008.264

A translucent, apple-green stone composed of microcrystalline Quartz. Chrysoprase is a variety of Chalcedony that contains small amounts of hydrated nickel silicate. The gemstone has occasionally been found in Egyptian, Greek, and Roman jewelry. Chrysoprase was also valued for mural decorations.

Synonyms and Related Terms

chalcedony; crisoprásio (Port.); Chrysopras (Deut.)

Physical and Chemical Properties

  • No visible crystals
  • Fracture = conchoidal, granular
  • Luster = waxy to greasy
  • Streak = white
  • Fluorescence = generally inert
  • Pleochroism = absent
Composition SiO2
Mohs Hardness 6.0-7.0
Density 2.65-2.91 g/ml
Refractive index 1.535 - 1.539
Birefringence 0.004 - 0.009

Comparisons

Properties of Common Gemstones

Resources and Citations

  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • Mineralogy Database: Quartz
  • Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
  • A.Lucas, J.R.Harris, Ancient Egyptian Materials and Industries, Edward Arnold Publishers Ltd., London, 4th edition, 1962
  • C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 647
  • Wikipedia: Chrysoprase Accessed Dec 2022.