Difference between revisions of "Onyx"

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[[File:99.101-37-3.jpg|thumb|]]
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[[File:99.101-37-3.jpg|thumb|Layered onyx<br>MFA# 99.101]]
 
== Description ==
 
== Description ==
  
A variety of [http://cameo.mfa.org/materials/fullrecord.asp?name=agate agate] that has parallel, alternating bands of [http://cameo.mfa.org/materials/fullrecord.asp?name=chalcedony chalcedony] and [http://cameo.mfa.org/materials/fullrecord.asp?name=opal opal]. The bands are usually colored black/white or red/white. In ancient times, the stones were available in Egypt, Arabia, and India. Onyx was often used as a gemstone in the production of cameos and intaglios. Onyx is also used as an ornamental building stone and for decorative items such as table tops, lamp bases, and small boxes. It was popularly used for geometric patterns in Art Deco designs of the 1920s. Limestone onyx, also called onyx marble, dark layers of impurities and polishes to a high gloss. [http://cameo.mfa.org/materials/fullrecord.asp?name=Mexican onyx Mexican onyx] is a banded limestone made from stalactites. Argentine onyx is a dark-green stone. [http://cameo.mfa.org/materials/fullrecord.asp?name=Sardonyx Sardonyx] has layers of sard (red carnelian) alternating with lighter-color layers of onyx.
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A variety of [[agate|agate]] that has parallel, alternating bands of [[chalcedony|chalcedony]] and [[opal|opal]]. The bands are usually colored black/white or red/white. In ancient times, the stones were available in Egypt, Arabia, and India. Onyx was often used as a gemstone in the production of cameos and intaglios. Onyx is also used as an ornamental building stone and for decorative items such as table tops, lamp bases, and small boxes. It was popularly used for geometric patterns in Art Deco designs of the 1920s. Limestone onyx, also called onyx marble, dark layers of impurities and polishes to a high gloss. [[Mexican%20onyx|Mexican onyx]] is a banded limestone made from stalactites. Argentine onyx is a dark-green stone. [[Sardonyx|Sardonyx]] has layers of [[sard]] (brownish) alternating with lighter-color layers of [[carnelian]] (red).
 
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[[File:Onyx brooch 5379.jpg|thumb|Onyx brooch<br>MFA# 53.79]]
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
  
agate; onyx marble; sardonyx; Mexican onyx; Onyx (Deut.); nice (Esp.); onyx(Fr.); onyks (Pol.); onix (Port.); onyx (Ned.)
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agate; onyx marble; sardonyx; Mexican onyx; Onyx (Deut.); ónice (Esp.); onyx(Fr.); onyks (Pol.); onix (Port.); onyx (Ned.)
  
== Other Properties ==
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== Risks ==
  
Birefringence = 0.009
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Inhalation of dust may be toxic resulting in silicosis.
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== Physical and Chemical Properties ==
  
{| class="wikitable"
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* Composition = SiO2
|-
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* No visible crystals
! scope="row"| Composition
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* Fracture = conchoidal, uneven, splintery
| SiO2
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* Luster = waxy to vitreous
|-
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* Streak = white 
! scope="row"| Mohs Hardness
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* Fluorescence = generally inert
| 7
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* Pleochroism = absent
|-
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* Mohs Hardness = 6.5 - 7.0
! scope="row"| Density
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* Density = 2.6
| 2.65-2.66
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* Refractive Index = 1.530 - 1.543
|-
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* Birefringence = 0.004 - 0.009
! scope="row"| Refractive Index
 
| 1.543-1.552; 1.545-1.554
 
|}
 
 
 
== Hazards and Safety ==
 
 
 
Inhalation of dust may be toxic resulting in silicosis.
 
  
 
== Comparisons ==
 
== Comparisons ==
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[[media:download_file_424.pdf|Properties of Common Gemstones]]
 
[[media:download_file_424.pdf|Properties of Common Gemstones]]
  
 
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== Resources and Citations ==
 
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* Gem Identification Lab Manual, Gemological Institute of America, 2016.
== Authority ==
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* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 565
 
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* Ralph Mayer, ''A Dictionary of Art Terms and Techniques'', Harper and Row Publishers, New York, 1969 (also 1945 printing)
* G.S.Brady, G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 565
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* Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982
 
 
* Ralph Mayer, Ralph Mayer, ''A Dictionary of Art Terms and Techniques'', Harper and Row Publishers, New York, 1969 (also 1945 printing)
 
 
 
* Jack Odgen, Jack Odgen, ''Jewellery of the Ancient World'', Rizzoli International Publications Inc., New York City, 1982
 
 
 
 
* ''Dictionary of Building Preservation'', Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
 
* ''Dictionary of Building Preservation'', Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
 
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* Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997
* Random House, Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997
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* A.Lucas, J.R.Harris, ''Ancient Egyptian Materials and Industries'', Edward Arnold Publishers Ltd., London, 4th edition, 1962
 
 
* A.Lucas, J.R.Harris, A.Lucas, J.R.Harris, ''Ancient Egyptian Materials and Industries'', Edward Arnold Publishers Ltd., London, 4th edition, 1962
 
 
 
 
* ''The American Heritage Dictionary'' or ''Encarta'', via Microsoft Bookshelf 98, Microsoft Corp., 1998
 
* ''The American Heritage Dictionary'' or ''Encarta'', via Microsoft Bookshelf 98, Microsoft Corp., 1998
 
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* Website: http://www.marble-institute.com
* Website address 1, Website address 1  Comment: http://www.marble-institute.com
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* Wikipedia: [https://en.wikipedia.org/wiki/Onyx#Varieties Onyx varieties] (Accessed Sept. 14, 2005 and Dec 2022)
 
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* Michael McCann, ''Artist Beware'', Watson-Guptill Publications, New York City, 1979
* Wikipedia, the free encyclopedia, at http://www.wikipedia.com  Comment: http://en.wikipedia.org/wiki/Onyx (Accessed Sept. 14, 2005)
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* Tom Rowland, Noel Riley, ''A-Z Guide to Cleaning, Conserving and Repairing Antiques'', Constable and Co., Ltd., London, 1981
 
 
* Michael McCann, Michael McCann, ''Artist Beware'', Watson-Guptill Publications, New York City, 1979
 
 
 
* Tom Rowland, Noel Riley, Tom Rowland, Noel Riley, ''A-Z Guide to Cleaning, Conserving and Repairing Antiques'', Constable and Co., Ltd., London, 1981
 
  
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Latest revision as of 11:00, 3 January 2023

Layered onyx
MFA# 99.101

Description

A variety of Agate that has parallel, alternating bands of Chalcedony and Opal. The bands are usually colored black/white or red/white. In ancient times, the stones were available in Egypt, Arabia, and India. Onyx was often used as a gemstone in the production of cameos and intaglios. Onyx is also used as an ornamental building stone and for decorative items such as table tops, lamp bases, and small boxes. It was popularly used for geometric patterns in Art Deco designs of the 1920s. Limestone onyx, also called onyx marble, dark layers of impurities and polishes to a high gloss. Mexican onyx is a banded limestone made from stalactites. Argentine onyx is a dark-green stone. Sardonyx has layers of Sard (brownish) alternating with lighter-color layers of Carnelian (red).

Onyx brooch
MFA# 53.79

Synonyms and Related Terms

agate; onyx marble; sardonyx; Mexican onyx; Onyx (Deut.); ónice (Esp.); onyx(Fr.); onyks (Pol.); onix (Port.); onyx (Ned.)

Risks

Inhalation of dust may be toxic resulting in silicosis.

Physical and Chemical Properties

  • Composition = SiO2
  • No visible crystals
  • Fracture = conchoidal, uneven, splintery
  • Luster = waxy to vitreous
  • Streak = white
  • Fluorescence = generally inert
  • Pleochroism = absent
  • Mohs Hardness = 6.5 - 7.0
  • Density = 2.6
  • Refractive Index = 1.530 - 1.543
  • Birefringence = 0.004 - 0.009

Comparisons

Properties of Common Gemstones

Resources and Citations

  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 565
  • Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
  • Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
  • Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
  • Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
  • A.Lucas, J.R.Harris, Ancient Egyptian Materials and Industries, Edward Arnold Publishers Ltd., London, 4th edition, 1962
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
  • Website: http://www.marble-institute.com
  • Wikipedia: Onyx varieties (Accessed Sept. 14, 2005 and Dec 2022)
  • Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979
  • Tom Rowland, Noel Riley, A-Z Guide to Cleaning, Conserving and Repairing Antiques, Constable and Co., Ltd., London, 1981