Difference between revisions of "Spessartite"

From The Gemology Project
Jump to: navigation, search
 
(22 intermediate revisions by 4 users not shown)
Line 1: Line 1:
 
{{spessartite}}
 
{{spessartite}}
  
[[Image:Spessgarnet.JPG|left|framed|"Mandarine" spessartite garnet]]<br clear="left" />
+
[[Image:Spessartite.jpg|left|thumb|300px|Nigerian Spessartite garnet<br />Photo courtesy of Lembeck Gems]]
 +
[[Image:Spess_china.jpg |left|thumb|300px| Spessartite with Smoky Quartz<br />Photo courtesy of Barbra Voltaire]]
 +
<br clear="left" />
 +
 
 +
{{images}}
 +
 
 +
Spessartite is also named spessartine, both names are used interchangeably.
 +
 
 +
==Diagnostics==
 +
 
 +
===Color===
 +
 
 +
Orange, red, reddish-orange to yellowish-brown.
 +
 
 +
===Spectroscope===
 +
 
 +
Spessartite shows a typical spectrum due to manganese (idiochromatic) and some iron (from [[almandine]]).
 +
 
 +
[[Image:Loliondospess.jpg|thumb|left|600px|Spectra of a spessartite from the Loliondo deposit in tanzania which was discovered in 2007. The graphs represent the transmission spectrum taken with the aid of a spectrometer, the spectrum below is what you will see through a spectroscope]]
 +
<br clear="left" />
 +
 
 +
===Inclusions===
 +
 
 +
* Feathers of liquid droplets ("shredded inclusions"), negative crystals, crystal inclusions, "suger"; multiple tiny grains (Tanzanian stones) ,  small colorless fibers of tirodite which cause a sleepy look (Namibian stones)
 +
 
 +
===Specific gravity===
 +
 
 +
4.12 - 4.20
 +
 
 +
Spessartite sinks in all common heavy liquids.
 +
 
 +
===Chelsea Colour Filter===
 +
 
 +
Spessartite will show red under the CCF.
 +
 
 +
==Varieties==
 +
 
 +
===Mandarine/Kashmirine/Hollandine===
 +
 
 +
Three names for the same intense orange variety of spessartite.
 +
 
 +
===Malaia===
 +
 
 +
:''Main entry: [[Pyrope#Malaia|pyrope]]''
 +
 
 +
Malaia garnet (or malaya garnet) is the red-orange variety of pyrope-spessartite.<br />
 +
 
 +
==Inclusion images==
 +
 
 +
[[Image:Mandarine garnet hf.jpg|left|thumb|240px|Inclusions in a manderine garnet<br />Photo courtesy of John Huff, gemcollections.com]]
 +
 
 +
[[Image:Spess3.JPG|thumb|280px|left|Double refractive crystal inclusion in a Loliondo, Tanzania spessartite.
 +
<br />
 +
© Tim Spauwen, FGA]]
 +
 
 +
[[Image:Spess2.JPG|thumb|300px|left|Crystal inclusions amidst the typical "sugary inclusions" in a Loliondo, Tanzania spessartite.
 +
<br />
 +
© Tim Spauwen, FGA]]<br />
 +
 
 +
[[Image:Spess_incl1.jpg|thumb|240px|left|Crystal Inclusions. <br /> © Jamey Swisher, RGA]]
 +
 
 +
 
 +
 
 +
 
 +
<br clear="all" />
 +
 
 +
==Localities==
 +
 
 +
{|
 +
|-
 +
|
 +
* Sri Lanka (Ceylon)
 +
|
 +
* Burma
 +
|
 +
* Brazil
 +
|-
 +
|
 +
* Madagascar
 +
|
 +
* Mozambique
 +
|
 +
* Nigeria
 +
|-
 +
|
 +
* Namibia
 +
|
 +
* Tanzania
 +
|
 +
* USA
 +
|-
 +
|
 +
* China
 +
|
 +
* Pakistan
 +
|
 +
* Afghanistan
 +
|-
 +
|
 +
* Myanmar
 +
|
 +
* India
 +
|
 +
* Italy
 +
|-
 +
|
 +
* Norway
 +
|
 +
* France
 +
|
 +
* Germany
 +
|-
 +
|
 +
* Sweden
 +
|
 +
* Scotland
 +
|
 +
* Russia
 +
|}
 +
 
 +
[[Image:SpessartiteGT.gif|left|thumb|240px|Faceted Mozambique Spessartite garnet<br />Photo courtesy of The Gem Trader]]<br clear="left" />

Latest revision as of 20:03, 3 October 2010

Spessartite Garnet
Chemical composition Mn3Al2(SiO4)3

Manganese aluminum silicate

Crystal system Cubic
Habit Dodecahedra
Cleavage None
Hardness 7
Optic nature Isotropic
Refractive index 1.795-1.815
Birefringence None
Specific gravity 4.12-4.20
Lustre Vitreous
Nigerian Spessartite garnet
Photo courtesy of Lembeck Gems
Spessartite with Smoky Quartz
Photo courtesy of Barbra Voltaire


Spessartite image gallery

Spessartite is also named spessartine, both names are used interchangeably.

Diagnostics

Color

Orange, red, reddish-orange to yellowish-brown.

Spectroscope

Spessartite shows a typical spectrum due to manganese (idiochromatic) and some iron (from almandine).

Spectra of a spessartite from the Loliondo deposit in tanzania which was discovered in 2007. The graphs represent the transmission spectrum taken with the aid of a spectrometer, the spectrum below is what you will see through a spectroscope


Inclusions

  • Feathers of liquid droplets ("shredded inclusions"), negative crystals, crystal inclusions, "suger"; multiple tiny grains (Tanzanian stones) , small colorless fibers of tirodite which cause a sleepy look (Namibian stones)

Specific gravity

4.12 - 4.20

Spessartite sinks in all common heavy liquids.

Chelsea Colour Filter

Spessartite will show red under the CCF.

Varieties

Mandarine/Kashmirine/Hollandine

Three names for the same intense orange variety of spessartite.

Malaia

Main entry: pyrope

Malaia garnet (or malaya garnet) is the red-orange variety of pyrope-spessartite.

Inclusion images

Inclusions in a manderine garnet
Photo courtesy of John Huff, gemcollections.com
Double refractive crystal inclusion in a Loliondo, Tanzania spessartite.
© Tim Spauwen, FGA
Crystal inclusions amidst the typical "sugary inclusions" in a Loliondo, Tanzania spessartite.
© Tim Spauwen, FGA

Crystal Inclusions.
© Jamey Swisher, RGA




Localities

  • Sri Lanka (Ceylon)
  • Burma
  • Brazil
  • Madagascar
  • Mozambique
  • Nigeria
  • Namibia
  • Tanzania
  • USA
  • China
  • Pakistan
  • Afghanistan
  • Myanmar
  • India
  • Italy
  • Norway
  • France
  • Germany
  • Sweden
  • Scotland
  • Russia
Faceted Mozambique Spessartite garnet
Photo courtesy of The Gem Trader