Difference between revisions of "Purple of Cassius"

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== Description ==
 
== Description ==
  
A permanent red-violet pigment.  Purple of Cassius was first made by Andreas Cassius in Germany in 1676.  It is composed of fine particle gold precipitated on hydrated stannic oxide when tin chlorides are mixed into a dilute gold chloride solution.  The addition of potassium carbonate to the solution deepens the purple color.  Purple of Cassius was used until the mid 19th century when it was replaced by cobalt violet.  The expensive pigment was used in miniature paintings and to make ruby glass and ceramic glazes.
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A permanent red-violet pigment.  Purple of Cassius was first made by Andreas Cassius in Germany in 1676.  It is composed of fine particle [[gold]] precipitated on hydrated stannic oxide when tin chlorides are mixed into a dilute [[gold chloride]] solution.  The addition of [[potassium carbonate]] to the solution deepens the purple color.  Purple of Cassius was used until the mid 19th century when it was replaced by [[cobalt violet]].  The expensive pigment was used in miniature paintings and to make [[ruby glass]] and ceramic glazes.  When [[tin]] is present as a red-violet painting pigment, there is also the possibility of [[cochineal]] prepared on a tin substrate.
  
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
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purple-of-Cassius; gold-tin purple; gold purple
 
purple-of-Cassius; gold-tin purple; gold purple
  
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== Physical and Chemical Properties ==
  
 
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* Soluble in ammonia. Insoluble in water.
 
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* Resistant to high temperatures.
== Other Properties ==
 
 
 
Soluble in ammonia.Insoluble in water.
 
Resistant to high temperatures
 
 
 
{| class="wikitable"
 
|-
 
! scope="row"| Composition
 
| Co (atomic no. 27)
 
|-
 
! scope="row"| CAS
 
| 7440-48-4
 
|-
 
! scope="row"| Melting Point
 
| 1493
 
|-
 
! scope="row"| Density
 
| 8.92
 
|-
 
! scope="row"| Molecular Weight
 
| atomic wt = 58.9332
 
|-
 
! scope="row"| Boiling Point
 
| about 3100
 
|}
 
 
 
== Hazards and Safety ==
 
 
 
Flammable solid. May explode when heated. Fumes may cause irritation or illness. Dust is toxic by inhalation.  Contact may cause irritation.  Potential carcinogen. 
 
 
 
Fisher Scientific: [https://fscimage.fishersci.com/msds/05250.htm MSDS]
 
 
 
== Additional Information ==
 
 
 
Web Elements: [http://www.webelements.com/webelements/elements/text/Co/key.html Website]
 
 
 
== Sources Checked for Data in Record ==
 
 
 
* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 60
 
 
 
* ''Van Nostrand's Scientific Encyclopedia'', Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
 
 
 
* Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997
 
 
 
* ''The Merck Index'', Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983  Comment: entry 2488
 
 
 
* ''The American Heritage Dictionary'' or ''Encarta'', via Microsoft Bookshelf 98, Microsoft Corp., 1998
 
 
 
* Website address 1  Comment: Web elements at http://www.webelements.com/webelements/elements/text/Co/hist.html
 
  
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Latest revision as of 06:54, 26 August 2020

Description

A permanent red-violet pigment. Purple of Cassius was first made by Andreas Cassius in Germany in 1676. It is composed of fine particle Gold precipitated on hydrated stannic oxide when tin chlorides are mixed into a dilute Gold chloride solution. The addition of Potassium carbonate to the solution deepens the purple color. Purple of Cassius was used until the mid 19th century when it was replaced by Cobalt violet. The expensive pigment was used in miniature paintings and to make Ruby glass and ceramic glazes. When Tin is present as a red-violet painting pigment, there is also the possibility of Cochineal prepared on a tin substrate.

Synonyms and Related Terms

purple-of-Cassius; gold-tin purple; gold purple

Physical and Chemical Properties

  • Soluble in ammonia. Insoluble in water.
  • Resistant to high temperatures.