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INVESTIGATIONS

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

Colour

Locality

Info

nx min

nx max

ny min

ny max

nz min

nz max

Spectrum

UVS

UVL

Reference

Orthoclase

1.517

1.528

0.011

0.011

2.58

2.58

yellowish

 

4.49ct

1.517

1.517

1.521

1.521

1.528

1.528

 

inert

inert

ACAM lab  2240

Orthoclase

1.518

1.526

0.008

0.008

2.56

2.56

greenish grey to light green

Sri Lanka

up to 3ct

 

 

 

 

 

 

 

 

 

The Australian Gemmologist 1982 may, p240

Orthoclase

1.519

1.53

0.011

0.011

2.55

2.55

colourless

Sri Lanka

2.08ct

 

 

 

 

 

 

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1999 Jul p106

Orthoclase

1.52

1.526

0.006

0.006

2.56

2.56

pink

Mogok, Myanmar

15.98ct, transparent , pink colour probably from Cr replacing Al

 

 

 

 

 

 

 

weak orange

weak orange

The Australian Gemmologist 2004 Vol 22, N°1, p32-34

Orthoclase

1.52

1.528

0.008

0.008

2.6

2.6

yellow brown , aventurescent, chatoyance and asterism

Tanzania

 

1.520

1.520

1.525

1.525

1.528

1.528

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2005 Mar, p43-46

Orthoclase

1.52

1.525

0.005

0.005

2.57

2.57

light orangy yellow

Mogok, Myanmar

15.21ct

 

 

 

 

 

 

line at 452nm

weak orange

weak orange

GIA Gem Database  34569

Orthoclase

1.52

1.524

0.004

0.004

2.57

2.57

yellow

Itrongahy, Betroka district, Toliara Province, Madagascar

25.33ct

 

 

 

 

 

 

420, 448nm lines

inert

inert

GIA Gem Database  33098

Orthoclase

1.52

1.524

0.004

0.004

2.57

2.57

yellow

Itrongahy, Betroka district, Toliara Province, Madagascar

58.57ct

 

 

 

 

 

 

broad absorption below 430nm, line at 453nm

weak red

weak orangy red

GIA Gem Database  34392

Orthoclase

1.521

1.529

0.008

0.008

2.58

2.58

green

Vietnam

transparent

 

 

 

 

 

 

none

moderate green

inert

Gems & Gemology 2005 winter, p354-355

Orthoclase

1.521

1.529

0.008

0.008

2.645

2.645

green

Felicio dos Santos, Minas Gerais, Brazil

"barium-orthoclase", 0.5ct

 

 

 

 

 

 

 

 

 

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1994 Jun, p5-13

Orthoclase

1.521

1.531

0.01

0.01

2.6

2.6

 

Norway

labradorescent; 85,7% orthoclase, 6.6% albite, 7.7% anorthite

1.521

1.521

1.527

1.527

1.531

1.531

 

 

 

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1994 Dez, p106

 

TABLES

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

nx min

 nx max

ny min

ny max

nz min

nz max

Reference

Orthoclase

1.508

1.536

0.005

0.008

2.55

2.61

 

 

 

 

 

 

Gemology Tools Professional 2010

Orthoclase

1.517

1.54

0.004

0.011

2.55

2.6

 

 

 

 

 

 

Gemmo.eu 

Orthoclase

1.518

1.539

 

 

2.55

2.63

1.518

1.529

1.522

1.533

1.522

1.539

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Orthoclase

1.518

1.53

0.007

0.009

2.55

2.57

 

 

 

 

 

 

Bestimmungstabellen für Edelsteine, Birgit Günther, 1981 

Orthoclase

1.518

1.536

0.005

0.009

2.55

2.6

1.518

1.519

 

 

1.526

1.536

Gemme, Dati per l'identificazione, P. De Stefano et al, 1993 

Orthoclase

1.518

1.539

0.004

0.007

2.55

2.63

 

 

 

 

 

 

http://www.gemmology.be 

Orthoclase

1.518

1.529

0.005

0.005

2.55

2.57

1.518

1.526

 

 

1.525

1.529

Tabellen zur Edelstein-Bestimmung, Pschichholz FGA, 1975 

Orthoclase

1.518

1.539

0.004

0.01

2.55

2.63

1.518

1.529

1.522

1.533

1.522

1.539

http://www.geminterest.com 

Orthoclase

1.518

1.539

0.012

0.012

2.55

2.63

1.518

1.529

 

 

1.522

1.539

Tables of Gemstone Identification, Roger Dedeyne, Ivo Quintens, 2007 

Orthoclase

1.52

1.54

0.005

0.008

2.56

2.57

 

 

 

 

 

 

John Sinkakas, Gemstone and mineral data book,1972 

Orthoclase

1.52

1.54

0.008

0.008

2.56

2.59

1.520

1.530

 

 

1.530

1.540

Gems, R Webster, 5th edition 1994 

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Orthoclase

pink

could be due to presence of Cr replacing Al

The Australian Gemmologist 2004, Vol 22, N°1, p34

Orthoclase

pink to red

microscopic hematite and/or lepidocrocite inclusions

Gems & Gemology Summer 1988

Orthoclase

yellow

Fe³+ in tetrahedral coordination

Gems & Gemology Summer 1988

 

MINERAL INCLUSIONS

 

LOCALITIES

 

CHEMICAL DATA (%)