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INVESTIGATIONS

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

Colour

Locality

Info

ne min

ne max

no min

no max

Spectrum

UVS

UVL

Reference

Chalcedony-Chrysoprase

1.53

1.55

0

0.006

2.56

2.57

dark green

Bolivia

Chrome chalcedony, translucent, chelsea: bright red

 

 

 

 

 

inert

yellowish

The Journal of Gemmology 1999 Vol 26, N6, p364-370

Chalcedony-Jasper

1.53

1.55

 

 

2.43

2.51

brownish (olive) green to green

 

translucent to opaque

 

 

 

 

cutoff at about 460 nm, and faint bands at 500 and 520 nm

inert

inert

Gems & Gemology 1996 Summer, p131

Chalcedony

1.531

1.539

 

 

2.55

2.57

bluish green

Africa

"aquaprase", translucent

 

 

 

 

faint, narrow lines in the red

 

 

Gems & Gemology 2015 Winter, p452-454

Chalcedony-Chrysoprase

1.532

1.54

0

0.005

2.56

2.58

dark green

 

translucent, chelsea : weak brownish red

 

 

 

 

 

inert

inert

The Journal of Gemmology 1999 Vol 26, N6, p364-370

Chalcedony

1.537

1.537

 

 

 

 

turquoise blue and near-colourless areas

Tanzania

chrome-chalcedony, cabochons

 

 

 

 

 

colourless areas: strong yellow green, blue parts: light yellow green

milky white

The Journal of Gemmology 2016 35 (3), p 189-190

Chalcedony

1.538

1.538

 

 

2.59

2.59

greyish violet

Qom area near the Qom Salt Lake, Iran

adularescent, 22.57 ct cabochon

 

 

 

 

 

inert

inert

Gems & Gemology 2004 Winter, p337

Chalcedony

1.538

1.538

 

 

2.58

2.58

green-blue

Arizona, USA

"gem silica", chrysocolla chalcedony, 1.24 ct

 

 

 

 

 

inert

inert

http://www.spec4gem.info/index.php 2016

Chalcedony-Chrysoprase

1.539

1.539

 

 

2.57

2.57

green

Newman, Western Australia

chrome chalcedony, translucent; chelsea : intense red

 

 

 

 

diffuse band in the orange 570-640nm,

inert

inert

The Journal of Gemmology 2003 Vol28, N5, p265-279

Chalcedony

1.539

1.539

 

 

2.64

2.64

light yellowish green

Brazil

semi-translucent

 

 

 

 

 

weaker greenish blue

moderate greenish blue

Gems & Gemology 1990 Summer, p156-157

Chalcedony-Chrysoprase

1.54

1.54

0

0.005

2.56

2.6

dark green

Zimbabwe

Chrome chalcedony, translucent, chelsea: bright red

 

 

 

 

 

pale yellowish in light parts

yellowish

The Journal of Gemmology 1999 Vol 26, N6, p364-370

Chalcedony

1.54

1.54

 

 

2.6

2.62

green-blue and blue-green

Iran

8.86 and 3.17 ct, cabochons, spot RI, chrysocolla chalcedony

 

 

 

 

650 nm cutoff

inert

inert

Gems & Gemology 2007 Winter, p376

Chalcedony

1.54

1.54

 

 

2.7

2.8

variegated green and dark grey

Applegate Valley in Jackson County, Oregon

2.31 - 13.38 ct, with pyrite and cloud-like green areas, spot RI

 

 

 

 

 

inert

inert

Gems & Gemology 2009 Fall, p217

Chalcedony

1.54

1.54

 

 

2.6

2.6

turquoise colour

Mexico

 

 

 

 

 

 

 

 

Gems & Gemology 1991 Spring, p40

Chalcedony

1.54

1.54

 

 

2.6

2.6

turquoise colour

Mexico

 

 

 

 

 

 

 

 

Gems & Gemology 1991 Spring, p40

Chalcedony

1.541

1.546

0.005

0.005

2.57

2.59

electric blue, greenish blue

 

translucent, chelsea filter: yellowish

 

 

 

 

two bands and a cut off in the red (660, 690)

inert

inert

Gems & Gemology 2007 fall, p265-266

Chalcedony-Chrysoprase

1.547

1.551

 

 

2.57

2.63

light to medium dark bluish green, opaque to translucent

Haneti, Tanzania

 

 

 

 

 

broad absorption below 450 and above 650nm

 

 

Gems & Gemology 2009 Winter, p271-279

 

TABLES

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

ne min

ne max

no min

no max

Reference

Chalcedony-Chrysoprase

1.526

1.545

0.004

0.009

2.57

2.64

1.539

1.545

1.526

1.535

http://www.geminterest.com 

Chalcedony

1.53

1.54

 

 

2.6

2.65

 

 

 

 

John Sinkakas, Gemstone and mineral data book,1972 

Chalcedony

1.53

1.539

0.004

0.006

2.55

2.64

1.534

1.539

1.530

1.535

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

Chalcedony

1.53

1.548

0.008

0.01

2.58

2.63

1.538

1.548

1.530

1.540

Gemmological Tables, Ulrich Henn, 2004 

Chalcedony

1.53

1.54

0.004

0.009

2.58

2.91

 

 

 

 

http://www.geminterest.com 

Chalcedony

1.53

1.539

 

 

2.58

2.62

 

 

 

 

Gems, R Webster, 5th edition 1994 

Chalcedony-Agate

1.53

1.54

0.004

0.004

2.55

2.63

 

 

 

 

Gemology Tools Professional 2010

chalcedony

1.53

1.54

0.004

0.004

2.55

2.63

 

 

 

 

Gemology Tools Professional 2010

Chalcedony-Chrysoprase

1.53

1.54

0.004

0.004

2.55

2.9

 

 

 

 

Gemology Tools Professional 2010

Chalcedony-Jasper

1.53

1.54

0.004

0.004

2.55

2.9

 

 

 

 

Gemology Tools Professional 2010

Chalcedony-Sard

1.53

1.54

0.004

0.004

2.55

2.9

 

 

 

 

Gemology Tools Professional 2010

Chalcedony

1.53

1.545

0.001

0.006

2.56

2.66

 

 

 

 

Gemmo.eu 2013

Chalcedony

1.535

1.539

0.004

0.006

2.55

2.65

 

 

 

 

Bestimmungstabellen fr Edelsteine, Birgit Gnther, 1981 

Chalcedony

1.535

1.539

0.004

0.008

2.58

2.64

 

 

 

 

http://www.gemmology.be 

Chalcedony

1.539

1.544

0.004

0.009

2.58

2.91

1.539

1.544

1.530

1.535

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

Chalcedony

1.54

1.54

0.004

0.009

2.61

2.91

 

 

 

 

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Chalcedony-Jasper

1.54

1.54

 

 

2.58

2.9

 

 

 

 

John Sinkakas, Gemstone and mineral data book,1972 

Chalcedony-Chrysoprase

1.544

1.553

0.008

0.009

2.65

2.67

 

 

 

 

http://www.gemmology.be 

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Chalcedony-Jasper

black

carbonaceous substances

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

black

Bitumen

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

black

MnO2

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

blue

Tyndall effect

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

chalcedony

blue to greenish blue (chrysocolla quartz)

microscopic to submicroscopic inclusions of chrysocolla

Gems & Gemology Summer 1988

Chalcedony-Chrysoprase

green

microscopic inclusions of nickeliferous clay-like material

Gems & Gemology Summer 1988

Chalcedony-Chrysoprase

green

pimelite nano-inclusions

The Australian Gemmologist 2002, Vol21, N8,p278

Chalcedony-Chrysoprase

green

Cr

The Journal of Gemmology 2003, Vol28, N5,p265

Chalcedony

green

dellesite, celadonite --> Chrysoprase

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

green

Cr bearing minerals  --> chromchalcedony

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

green

Chlorite--> Heliotrope (with red spots= hematite)

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

green

Actinolite inclusions

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

greenish blue

Chrysocolla inclusions

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

grey

different levels of Fe+-oxides and Fe+-oxides = ratio Fe+/Fe+

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony-Jasper

orange to red

microscopic to submicroscopic inclusions of hydrous Fe oxides

Gems & Gemology Summer 1988

chalcedony

purple

microscopic  inclusions of sugilite

Gems & Gemology Summer 1988

chalcedony

purple (damsonite)

colour center similar to that found in amethyst

Gems & Gemology Summer 1988

Chalcedony

red, red brown, yellowish red

inclusions of Fe (III) oxihydroxide (FeOOH) = hematite

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

violet

red colouring pigments and Tyndall-effect

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

white

scattering of light on submicroscopic particles

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

yellow green

yellow-brown colouring pigments and und Tyndall-effect

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

yellow, yellow brown, brown, orange

inclusions of Fe (III) oxihydroxide (FeOOH) = goethite

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

Chalcedony

yellow-white

inclusions of kaolinite

Gemmologie, Zeitschrift der deutschen gemmologischen Gesellschaft Mar 2004, p25

 

MINERAL INCLUSIONS

Inclusion

Stone

Reference

anhydrite

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

aragonite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

aurichalcite

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

barite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

calcite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

celadonite

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

celestine

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

chrysocolla

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

dolomite

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

goethite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

gypsum

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

hematite

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

limonite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

marcasite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

pyrolusite

Chalcedony-Agate

The Australian Gemmologist, 2004, Vol22, N1, p26-27

quartz

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

rutile

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

siderite

Chalcedony-Agate

Gems & Gemology 1978 spring p16-28

 

LOCALITIES

STONE

LOCALITIES

REFERENCE

agate-Chalcedony

Sunnyside, Ireng River

34km N of Lethem

 

Guyana

The Journal of Gemmology 1990, Vol22, N2, p76-79

agate-Chalcedony

 

Ambatolampy

Antananarivo

Madagascar

Gemmologie, Dez 1999,p196

agate-Chalcedony

Antsirab

Vakinankaratra Region (Betafo - Antsirab region)

Antananarivo Province

Madagascar

Gemmologie, Dez 1999,p196

agate-Chalcedony

 

Boriziny

Mahajanga (Majunga) Province

Madagascar

Gemmologie, Dez 1999,p196

agate-Chalcedony

Ambatondrazaka District

Alaotra-Mangoro Region

Toamasina (Tamatave) Province

Madagascar

Gemmologie, Dez 1999, p196

agate-Chalcedony

 

Mahenge

Morogoro Region

Tanzania

Gemmologie, 1997, Mar,p31

Chalcedony

 

Finishi Village

 

Malawi

Gemmologie Jun 2006 -p34

Chalcedony

 

Saricakaya

Eskisehir Province

Turkey

Cigdem Lule-Whipp (2006) Gems & Gemology, 42, 115.

chrome-chalcedony

 

Newman

Western Australia

Australia

The Journal of Gemmology 2003, Vol28, N5, p265-279

chrome-chalcedony

Rincon del Tigre

Chiquitos Province

Santa Cruz Department

Bolivia

Jaroslav Hyrsl and Alfredo Petrov (1998) Journal of Gemmology, 26, 1, 43.

chrome-chalcedony

 

Mtoroshanga (Mutorashanga)

Mashonaland West

Zimbabwe

Phillips, G. & Brown, G. (1989) Mtorolite. Australian Gemmologist

chrysoprase-Chalcedony

 

Marlborough Area

Queensland

Australia

Gems & Gemology 1965, Fall, p323

chrysoprase-Chalcedony

Wingellina Community, West Musgrave Block

Ngaanyatjarraku Shire

Western Australia

Australia

Australian Lapidary Magazine, Vol. 17, No. 8, 198 1, pp. 17-19.

chrysoprase-Chalcedony

 

Hanety Hill (Haneti)

 

Tanzania

Peter Bancroft’s classic book, Gem and Crystal Treasures (1984) Western Enterprises/Mineralogical Record, Fallbrook, CA, 488 pp

Fire agate - Chalcedony

Deer Creek Fire Agate Mine

Graham County

Arizona

USA

Gems & Gemology 1919 Spring p130-141

jasper-Chalcedony

 

Orinduik Falls

 

Guyana

The Journal of Gemmology 1986, 20, 2, p91-92

jasper-Chalcedony

Maevatanana District

Betsiboka Region

Mahajanga (Majunga) Province

Madagascar

Gemmologie, Dez 1999, p196

jasper-Chalcedony

 

Boriziny

Mahajanga (Majunga) Province

Madagascar

Gemmologie, Dez 1999,p196

jasper-Chalcedony

Ambatondrazaka District

Alaotra-Mangoro Region

Toamasina (Tamatave) Province

Madagascar

Gemmologie, Dez 1999, p196

jasper-Chalcedony

Swierki

Klodzko District

Lower Silesia (Dolnoslaskie)

Poland

Journal of Gemmology, Vol. 33, N6, 1993, pp. 356-359.

mtorolite-Chalcedony

 

Mtoroshanga (Mutorashanga)

Mashonaland West

Zimbabwe

Phillips, G. & Brown, G. (1989) Mtorolite. Australian Gemmologist

 

CHEMICAL DATA

Stone

Colour

Locality

Reference

SiO2

Al2O3

MnO

MgO

TiO2

CaO

Na2O

Cr2O3

Fe2O3

K2O

H2O

NiO

Chalcedony-Agate

dyed blue

 

 

The Journal of Gemmology 2000, Vol 27, N5,p282

99.98

 

 

 

 

0.02

 

 

 

0.03

 

 

Chalcedony

dyed green

 

 

The Journal of Gemmology 1999, Vol 26, N6, p364-370

98.92

0.16

 

 

 

 

 

0.28

 

 

 

 

Chalcedony-Chrysoprase

green (coloured by Cr)

Newman, Western Australia

Australia

The Journal of Gemmology 2003, Vol 28,N5, p273

95.01

0.29

0.01

0.46

 

 

 

0.24

1.45

 

2.22

0.01

Chalcedony-Chrysoprase

dark green (Cr chalcedony)

 

Bolivia

The Journal of Gemmology 1999, Vol 26, N6, p364-370

95.9

0.09

 

0.11

0.09

 

 

0.36

 

 

 

 

Chalcedony-Chrysoprase

light green (Cr chalcedony)

 

Bolivia

The Journal of Gemmology 1999, Vol 26, N6, p364-370

96

0.13

 

0.15

 

 

 

0.51

 

 

 

 

Chalcedony-Jasper

red-grey

Swierki, Noda Ruda

Poland

The Journal of Gemmology 1993, Vol23, N6, p356-359

77.79

4.44

 

3.29

0.12

4.15

0.28

 

0.59

1.95

 

 

Chalcedony-Jasper

green

Swierki, Noda Ruda

Poland

The Journal of Gemmology 1993, Vol23, N6, p356-359

77.89

8.46

 

2.05

0.34

0.43

0.34

 

1.85

3.48

 

 

Chalcedony-Agate

blue

 

Taiwan

The Journal of Gemmology 2000, Vol 27, N5,p282

99.62

 

 

 

0.01

0.07

0.24

 

 

0.03

 

 

Chalcedony-Agate

blue

 

Taiwan

The Journal of Gemmology 2000, Vol 27, N5,p282

99.68

 

 

0.11

 

0.11

 

0.04

0.01

0.05

 

 

Chalcedony-Chrysoprase

dark green (Cr chalcedony)

 

Zimbabwe

The Journal of Gemmology 1999, Vol 26, N6, p364-370

93.56

0.29

0.08

0.3

 

 

 

0.45

 

 

 

 

Chalcedony-Chrysoprase

light green (Cr chalcedony)

 

Zimbabwe

The Journal of Gemmology 1999, Vol 26, N6, p364-370

94.38

0.18

 

0.16

 

 

 

0.21