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INVESTIGATIONS

Stone

RI min

RI max

Dens min

Dens max

Colour

Info

Spectrum

UVS

UVL

Reference

Glass

1.456

1.456

2.25

2.25

transparent smoky brown

 

 

green

green

Gems & Gemology 1976 Spring, p155

Glass

1.47

1.47

2.51

2.51

red

30.12ct, resembles a color-zoned rubellite

 

strong chalky blue

inert

Gems & Gemology 2008 summer, p186

Glass

1.48

1.48

2.69

2.69

green

"meta-jade", partly devitrified, 22.69 ct

general absorption below 480 and above 560

weak yellowish green

faint yellowish green

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1993 Dec, p171-177

Glass

1.49

1.49

2.18

2.18

turquoise

0.81 ct bead, turquoise imitation, semi-transparent, impregnated!

 

 

 

Gems & Gemology 2007 Winter, p365

Glass

1.506

1.508

2.51

2.56

blue, opaque

imitating lapis lazuli, devitrified glass

 

 

 

The Journal of Gemmology 1987 Vol 20, N5, p285-286

Glass

1.508

1.508

2.453

2.453

violetish blue of strong saturation, opaque to semitranslucent, translucent, to transparent

hardness +/- 5.5

 

inert

extremely weak

Gems & Gemology 1983 winter, p228-2231

Glass

1.51

1.56

 

 

colourless, blue, green, orange, red

pit glass = prehistoric (?) manmade (Sri Lanka)

 

 

 

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1993 Mar, p27-36

Glass

1.514

1.514

2.47

2.47

colourless with opalescence

"slocum stone", imitation opal, H: 5-5.5

 

inert

inert

Gems & Gemology 1976 Winter, p252-256

Glass

1.516

1.516

2.64

2.64

light grey

 

cordierite imitation, 15.6ct

 

 

The Journal of Gemmology 1977 N3,p117-118

Glass

1.518

1.521

2.48

2.5

colourless (i.e., water opal simulant), white, black, and blue bodycolors

"mermaid crystal" , opal simulant

 

moderate to moderately strong yellow

inert

Gems & Gemology 2003 Fall, p239

Glass

1.518

1.53

2.5

2.52

yellowish green to green

represented as natural green obsidian

dark in the blue and in the red

inert, faint yellow, or weak to medium green

inert

Gems & Gemology 1998 Fall, p129

Glass

1.519

1.52

2.47

2.53

green, yellow, blue

trade name : lazerite

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1995 Mar, p8

Glass

1.52

1.52

2.51

2.51

green

3.76 and 3.80ct, moldavite imitation

 

 

 

Gems & Gemology 2016 Winter, p431-433

Glass

1.52

1.52

2.55

2.55

 

inclusions of synthetic wollastonite crystals and synthetic diopside crystals as divitrification product

 

 

 

Gems & Gemology 2010 summer, p144

Glass

1.52

1.52

2.65

2.65

orangy red

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.521

1.521

2.66

2.66

colour change: bluish-green in some fluorescent light (not daylight! Corrected in an erratum), purplish pink in incandescent light

trade-marked as "zandrite"

rear earth spectrum (a lot of lines)

inert

very weak bluish green

Gems & Gemology 2004 spring, p73

Glass

1.524

1.524

2.395

2.395

dark bluish grey in daylight, light yellow in incandescent light

9.57ct

 

chalky yellow

slight green

Gems & Gemology 2009 Spring

Glass

1.53

1.53

2.31

2.31

green

to imitate emerald

 

 

 

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1992 Sep, p66

Glass

1.53

1.53

2.84

2.84

blue-green

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.53

1.53

3.38

3.38

 

opal imitation

 

 

 

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1989 Dec, p139-142

Glass

1.537

1.537

2.64

2.64

bluish purple

 

moderate band in the yellow at 580 nm

inert

inert

Gems & Gemology 1996 Winter, p270-276

Glass

1.538

1.538

2.82

2.82

colour change: violet-blue in fluorescent light (not daylight!), reddish purple in incandescent light

trade-marked as "zandrite"

rear earth

inert

inert

Gems & Gemology 2005 winter, p364

Glass

1.545

1.545

2.91

2.91

green, colour change to red

1.18ct

 

inert

inert

ACAM lab  1652

Glass

1.549

1.549

2.75

2.75

colour-changing :yellowish green to brownish pink

diaspor imitation

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2013 62/1-2, Jun, p52

Glass

1.55

1.55

3.09

3.09

reddish orange

spot RI, 2.85ct cabochon, fiber optic glass, cat's-eye

 

chalky whitish yellow

dull red

Gems & Gemology 1996 Fall, p222

Glass

1.56

1.56

2.99

2.99

"cobalt" blue

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.56

1.56

3.11

3.11

light blue

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.57

1.57

3.12

3.12

violetish brown

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.57

1.57

3.14

3.14

grey

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.57

1.57

3.18

3.18

white

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.57

1.57

 

 

irregular layers of green

imitation of malachite, cabochon

 

inert

white (light green bands)

The Journal of Gemmology 2014 Vol 34, N4, p 299

Glass

1.58

1.58

3.2

3.2

dark green

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.58

1.58

3.2

3.2

pink

Chinese fiber glass, imitation cat's-eye

 

 

 

Gems & Gemology 2003 Winter, p 339

Glass

1.6

1.6

2.72

2.72

dark green

Devitrified, resembling actinolite, 12.25 ct

absorption increasing toward both ends of the spectrum, with a transmission window from about 540 to 580 nm

 

 

Gems & Gemology 1993 Fall, p201

Glass

1.6

1.6

2.98

2.98

green

"Swarogreen", emerald imitation, 0.22 carat

 

 

greenish-yellow

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1994 Dez, p107

Glass

1.6

1.605

3.36

3.48

blue-violet

"U.M.Tanzanic" tanzanite imitation, 2.89 ct and 0.92 ct

weak absorption bands at approximately 490,550, and 590 nm

chalky white

chalky white

Gems & Gemology 1996 Winter, p270-276

Glass

1.606

1.606

2.99

2.99

mottled brownish green

sphere, opaque, obsidian imitation, numerous spherical inclusions with a silvery metallic luster

no features

inert

inert

Gems & Gemology 1998 winter, p 301

Glass

1.608

1.612

2.88

2.94

 

"Swarogreen", 0.08 to 0.42 ct

strong, broad doublet at about 442 and 448 nm, a triplet at 466, 472, and 483 nm; broad band centered at 590 nm.

weak green

weak to faint yellowish green to greenish yellow

Gems & Gemology 1994 Summer, 130

Glass

1.614

1.636

3.4

3.5

 

partially devitrified imitation of hemimorphite

 

weak chalky blue, greenish yellow

inert

Gems & Gemology 2012 Summer, p153

glass-ceramic

1.621

1.629

3.02

3.07

blue, green

"nanogems", 2.59-3.15ct, aggregate reaction in polariscope; hardness 7-7.5 (according to company)

 

inert to weak white (blue samples)

inert

Gems & Gemology 2010 summer, p156-157

Glass

1.63

1.63

3.69

3.69

brown

smoky quartz imitation, 19.95ct

 

strong green-yellow

moderate reddish brown

ACAM lab  4781

Glass

1.635

1.635

3.754

3.754

emerald green

radio-active (up to 0.02 mR/h)

 

 

 

The Journal of Gemmology 1992 Vol23, N2, p80-82

Glass

1.647

1.647

3.87

3.87

dark blue

 

Co bands

greyish

inert

ACAM lab  1183

Glass

1.65

1.65

3.87

3.87

pink

10.4ct

 

bluish

inert

ACAM lab  2096

Glass

1.661

1.661

3.37

3.37

green

aluminosilicate glass

 

inert

inert

The Journal of Gemmology 2016 35 (3), p 205-206

Glass

1.68

1.68

4.14

4.14

pinkish red

19.41ct

 

greenish

yellow-green

ACAM lab  1299

Glass

1.681

1.681

4.16

4.16

dark red

27.76ct

 

greenish

inert

ACAM lab  1372

Glass

1.7

1.7

4.11

4.11

violetish blue

5.42ct, tanzanite imitation

weak bands at 500 and 600 nm

blue

weak blue

Gems & Gemology 2003 Winter, p317-318

Glass

1.71

1.71

4.01

4.01

blue

tanzanite imitation

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2004 Dec, p125

Glass

1.73

1.73

4.36

4.36

green

17.5 ct, emerald imitation

no absorption features

inert

inert

Gems & Gemology 2010 summer, p155-156

Glass

1.74

1.74

3.66

3.66

 

12ct, tsavorite imitation

general absorption around 500 nm

strong chalky yellow

inert

Gems & Gemology 2003 Summer, p146

Glass

1.745

1.745

4.33

4.33

emerald green

translucent, with crystalline aggregates, 25.04 ct

 

chalky blue

inert

Gems & Gemology 2010 Winter, p 328-329

Glass

 

 

4.43

4.43

greenish brown

peridote imitation, high dispersion

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2004 Dec, p125-126

Glass

 

 

4.43

4.43

green

26.82ct, peridot imitation

 

 

 

Gems & Gemology 1999 spring p 44

Glass

 

 

4.44

4.44

red, blue, green, yellow, brown, black

hardness 6, RI about 2

 

 

 

Gems & Gemology 1993 winter, p289

Glass

 

 

4.65

4.65

green

barium-zirconium glass, peridot imitation

 

inert

inert

Gems & Gemology 2009 Winter, p307

Glass

 

 

6.58

6.58

intense yellow

IR OTL, 27.73 ct, contains Pb

general absorption from 439nm

inert

inert

Gems & Gemology 2003 Summer, p147

 

TABLES

Stone

RI min

RI max

Dens min

Dens max

Reference

Glass

1.44

1.9

2.3

4.5

Bestimmungstabellen fr Edelsteine, Birgit Gnther, 1981 

Glass

1.44

1.962

2.3

5.12

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

Glass

1.44

1.77

2.2

4.55

Tabellen zur Edelstein-Bestimmung, Pschichholz FGA, 1975 

Glass

1.44

1.9

2.3

4.5

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

Glass

1.44

1.7

2.08

4.3

Gemmo.eu 2013

Glass

1.47

1.7

2.3

4.5

Gemology Tools Professional 2010

Glass

1.48

1.7

2.39

4

Gemmological Tables, Ulrich Henn, 2004 

Glass

1.7

2.1

4.3

5

Gemmo.eu 2013

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Glass (Chinese fiber)

black, green, yellow, orange, brown, blue

Black was associated with traces of Mn; green with Cu, Cr, and/or Fe; yellow to orange to brown with Fe; and bright blue with Co.

Gems & Gemology 2003 winter, p340

 

CHEMICAL DATA

Stone

Colour

Made in

Reference

SiO2

Al2O3

MnO

MgO

TiO2

CaO

Na2O

Cr2O3

ZnO

Fe2O3

K2O

CuO

H2O

CoO

P2O5

PbO

ZrO2

BaO

As2O3

Glass

olive standard; industriel

 

 

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

71.68

1.96

0.01

2.88

0.05

10.1

12.44

 

 

0.1

0.51

 

 

 

 

 

 

 

 

Glass

brown standard; industriel

 

 

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

69.65

2.15

0.03

3.03

0.05

9.73

13.64

 

 

0.3

1.35

 

 

 

 

 

 

 

 

Glass

green standard; industriel

 

 

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

71.57

1.65

0.22

2.12

0.06

10.29

12.71

 

 

0.33

0.67

 

 

 

 

 

 

 

 

Glass

blue (chalcedony imitation)

 

Taiwan

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

72.97

0.45

 

3.86

0.02

9.13

13.09

0.01

 

0.17

0.31

 

 

 

 

 

 

 

 

Glass

dark brown standard; industriel

 

 

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

78.02

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Glass

blue (chalcedony imitation)

 

Taiwan

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

73.3

0.34

 

3.85

0.02

9.11

12.98

0.01

 

0.14

0.26

 

 

 

 

 

 

 

 

Glass

blue (chalcedony imitation)

 

Taiwan

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

73.01

0.33

 

3.86

0.02

8.54

13.83

0.01

 

0.14

0.26

 

 

 

 

 

 

 

 

Glass

colourless, slightly greenish

"pit glass"

Sri Lanka

Zeitschrift der deutschen gemmologischen Gesellschaft, 1993, Mar, p31

68.9

1.7

0.02

2.06

0.03

12.5

11.9

 

0.3

0.2

0.86

 

0.1

 

0.03

0.34

0.1

0.02

0.05

Glass

cobalt blue

"pit glass"

Sri Lanka

Zeitschrift der deutschen gemmologischen Gesellschaft, 1993, Mar, p31

69.1

2.6

0.06

0.02

0.05

7.7

14.3

 

3.2

0.06

0.91

0.6

0.15

0.07

0.05

 

0.03

0.002

0.3

Glass

emerald green

"pit glass"

Sri Lanka

Zeitschrift der deutschen gemmologischen Gesellschaft, 1993, Mar, p31

67.6

2.8

0.02

0.02

0.01

11.5

13.6

0.2

0.03

0.07

2.07

0.14

0.16

 

0.07

0.04

 

0.005

0.4

Glass

light blue

"pit glass"

Sri Lanka

Zeitschrift der deutschen gemmologischen Gesellschaft, 1993, Mar, p31

58.4

15

0.2

0.05

0.2

1.3

9.16

 

0.09

0.2

1.28

0.25

0.56

 

0.11

11.2

0.1

 

0.65

Glass

orange

"pit glass"

Sri Lanka

Zeitschrift der deutschen gemmologischen Gesellschaft, 1993, Mar, p31

70.1

1.6

0.09

0.04

0.03

10.1

10.88

 

0.12

0.06

4.99

0.06

0.34

 

0.08

0.16

 

0.01

0.3

Glass

red

"pit glass"

Sri Lanka

Zeitschrift der deutschen gemmologischen Gesellschaft, 1993, Mar, p31

53.4

2

0.18

0.02

0.006

0.8

14.8

 

0.06

0.12

0.22

0.07

1.26

 

0.22

26.2

 

 

0.5

Glass

 

"slocum stone"

 

Gems & Gemology 1976, Winter, p256

72.5

0.51

 

4.32

 

8.29

13.65

 

 

 

0.31