Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

Colour

Location

Info

ne min

ne max

no min

no max

Spectrum

UVS

UVL

Reference

Corundum - Sapphire

3,98

4,013

light to medium blue, light to medium violet

Yogo Gulch, Montana (USA)

lamprophyric rock intruded in limestone; most are brillant cuts and <0.5 ct

weak Fe, violet stones may show Fe-Cr combination

inert, violet may show weak to moderate red

inert, violet may show weak to moderate red

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

near colourless, medium blue, medium green, purple, pink to red, medium yellow, greenish yellow, orangy yellow, orange, six-stars

Missouri River, Dry Cottonweed Creek & Rock Creek (Montana, USA)

not reported

inert, red may show weak to moderate red

inert, red may show weak to moderate red

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

neon-blue

Co spectrum besides a  Fe spectrum

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2009 58/3-4/Dec, p88-89

Corundum - Sapphire

1,757

1,774

0,008

0,009

3,95

4,1

near colourless to deep blue, often light blue , slightly more violet than Sri Lanka, purple to violet, yellow, rarely green, 6-rayed stars; colour is exceptionally even

Mogok (Birma)

variety of enveronments: pegmatites, syenites, gneisses, urtites

1,757

1,765

1,766

1,774

weak to strong Fe

generally inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,758

1,766

0,008

0,008

3,99

4,01

yellow, colourless, blue

Kimmirut, Baffin Island, Canada

very weak orange

moderate orange

Gems & Gemology 2004 winter p344

Corundum - Sapphire

1,758

1,767

0,009

0,009

pale to dark pink

Kootchinskoye deposit, Ural Mts, Russia

<1ct

Gems & Gemology 1994 winter p243-252

Corundum - Sapphire

1,758

1,767

0,007

0,007

3,91

4,35

bluish grey

Santa Terezinha de Goias, Brazil

only for cabochon, translucent

1,758

1,760

1,765

1,767

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1986 Jg 35, Nr 1/2,p15-19

Corundum - Sapphire

1,758

1,77

0,008

0,01

3,98

4,02

Blue, grey, bicolored pink and blue, violetish blue, purplish pink, colourless

Sutara, Jewish Autonomous Oblast' Russia

1,767

1,770

1,758

1,762

inert, purplish pink stones: inert to weak red

inert,  purplish pink stones:moderate to strong red

Gems & Gemology 2016 Fall, p 252-264

Corundum - Sapphire

1,759

1,768

0,008

0,008

4

4,03

purplish pink

Batakundi, Pakistan

1,759

1,760

1,767

1,768

very weak red

moderate to strong red

Gems & Gemology 2004 winter p343

Corundum - Sapphire

1,759

1,78

0,008

0,01

3,96

4,05

orange, yellow, blue to green, red

Malawi

epidotized amphibolite

1,759

1,770

1,768

1,780

Cr , Fe or combination

generally inert, red stones may show weak red

generally inert, red stones may show weak red

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,759

1,776

0,008

0,009

3,98

4,01

blue to greenish blue, typically inky

Nigeria

weathered alkali basalts

1,759

1,768

1,768

1,776

strong Fe spectra

generally inert

generally inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,759

1,771

0,08

0,008

3,99

4,02

red, blue, violet, purple, yellow, orange, rarely green, 6-rayed stars common, colourless

Sri Lanka

granites

1,759

1,763

1,767

1,771

red, purple, violet : Cr; bue : weak to moderate Fe

blue: inert to moderate red, heat treated: chalky blue green; red : moderate to strong red; yellow: moderate orange

blue: inert to strong red; red : moderate to strong red; yellow: moderate orange

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,759

1,77

0,008

0,008

3,97

3,99

pink to light red, reddish violet

Nepal

1,759

1,762

1,767

1,770

intens reddish-orange

stronger than UVS:intens reddish-orange

The Australian Gemmologist 1982 may, p225-229

Corundum - Sapphire

1,759

1,77

0,011

0,011

3,09

3,09

greenish brown

Sri Lanka

absorption lines in blue and violet

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1998 Sep, p169

Corundum - Sapphire

1,759

1,77

0,009

0,009

3,99

4,01

very dark inky blue, yellow

Kaduna Province, Nigeria

1,768

1,770

1,759

1,761

The Journal of Gemmology 1987 Vol 20, N°7/8 p427-442

Corundum - Sapphire

1,759

1,771

0,008

0,009

3,98

4,04

pink, purplish pink, light to dark blue

Quy Chau - Quy Hop, Nghe An,  Vietnam

1,767

1,771

1,759

1,762

blue: light blue, orange

blue: light blue, orange

Gems & Gemology 2012 Fall, p165

Corundum - Sapphire

1,759

1,769

0,008

0,009

medium to medium dark blue to slightly violetish blue

Madagascar

1,759

1,760

1,768

1,769

Fe lines

inert to weak challky greenish blue

inert

Gems & Gemology 1995 Summer, p132-133

Corundum - Sapphire

1,759

1,769

0,01

0,01

4

4

pink

Mozambique

11.16ct

Gems & Gemology 2020 Summer p286

Corundum - Sapphire

1,76

1,769

0,008

0,008

3,98

4

orange pink, purplish pink, blue

Ilakaka, Madagascar

pink : Cr ; blue : 450 band

very weak orange ; blue : inert to chalky yellowish green

moderate to strong orange; blue : inert to very weak red

Gems & Gemology 1999 summer p149

Corundum - Sapphire

1,76

1,778

0,008

0,008

3,97

4,06

red-orange, light blue, blue-green, green, light yellow, colour change, no stars; colour often lighter at the core

Umba Valley (Tanzania)

pegmatite veins

1,760

1,769

1,768

1,778

Cr and Fe spectra, rarely V

generally inert

generally inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,76

1,77

0,008

0,008

3,993

4,007

light to deep blue, black stars

Pailin (Cambodia)

weathered alkali basalts

1,760

1,762

1,768

1,770

moderate to strong Fe

inert

inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,76

1,772

0,008

0,009

3,99

4,02

pale to deep blue to bluish green; most stones are of a dark, inky blue

southern Vietnam

alkali basalts

1,760

1,764

1,769

1,772

strong Fe

inert

inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,76

1,772

0,008

0,01

4

4,02

medium to dark blue to violet/purple

Indaia (Brasil)

1,760

1,762

1,768

1,772

sometimes weak 450nm band

moderate to strong red

inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,76

1,77

0,008

0,009

3,94

4,01

red to pink, purplish pink, often with visible violetish blue color banding

Ganesh HimalNepal

1,760

1,762

1,769

1,770

468 line, 475 line, 476 line, 525-585 band, 659 line, 668 line, 692 line, 694 line

red: faint to moderate red; violet : inert

red : moderate to very strong red; violet : inert

Gems & Gemology 1997 spring p24-41

Corundum - Sapphire

1,76

1,772

0,008

0,01

4

4,02

blue to violetish blue to purple, colour change (violet in daylight-purple in incandescent light)

Indaia, Minas Gerais, Brazil

geology: Precambrian complexes of metamorphic besement rocks

1,760

1,762

1,768

1,772

faint band at 450nm

inert

moderate to strong bright red

Gems & Gemology 1994 spring, p24-32

Corundum - Sapphire

1,76

1,772

0,008

0,01

3,96

4

Nigeria

1,760

1,764

1,770

1,772

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1986 Jg 35, Nr 1/2,p15-19

Corundum - Sapphire

1,76

1,768

0,008

0,008

4

4

blue

Elahera, Sri Lanka

450nm, 460nm

light blue

Gems & Gemology 1986 Summer, p87

Corundum - Sapphire

1,76

1,768

0,008

0,008

4,01

4,01

yellow

Elahera, Sri Lanka

694, 692nm

apricot orange

apricot reddish

Gems & Gemology 1986 Summer, p87

Corundum - Sapphire

1,76

1,768

0,008

0,008

4

4

padparadscha

Elahera, Sri Lanka

694 and 692nm

strong apricot

Gems & Gemology 1986 Summer, p87

Corundum - Sapphire

1,76

1,77

0,008

0,008

3,98

4

blue, pink, colourless, pale green, yellow, orange, pale brown, brownish red, violet

Madagascar

up to 15ct

1,760

1,762

1,768

1,770

The Journal of Gemmology 2001 Vol27, N°7,p385-394

Corundum - Sapphire

1,76

1,773

0,008

0,008

3,98

4,03

blue, blue-violet, greenish blue, greenish-yellow, yellow

Nosy-Bé, Madagascar

Basalt

1,768

1,773

1,760

1,765

inert

inert

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2004 Dec, p143-158

Corundum - Sapphire

1,76

1,769

0,009

0,009

3,98

3,98

colourless

Sri Lanka

1.4ct

pinkish-orange

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1999 Jul p106

Corundum - Sapphire

1,76

1,771

0,008

0,008

3,99

4,02

Indaia, Minas Gerais, Brazil

1,760

1,763

1,768

1,771

band 500-600nm (Fe²+/Ti4+) and  450nm (Fe³+)

inert

inert, sometimes reddish

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1994 Dez, p111-116

Corundum - Sapphire

1,76

1,77

0,008

0,009

3,94

4,09

pink and blue

Muling, Heilongjiang, China

1,760

1,762

1,768

1,770

Gems & Gemology 2011 Summer, p136

Corundum - Sapphire

1,76

1,77

0,008

0,008

4

4

blue

Thammannawa, Kataragama area, Sri Lanka

1,768

1,770

1,760

1,762

line at 450nm

inert

weak red

Gems & Gemology 2012 Summer, p98-107

Corundum - Sapphire

1,76

1,769

0,008

0,009

4

4

purplish pink to orangy pink, brownish pinkish purple, bicolored reddish purple and reddish
orange

Tamil Nadu, India

0.36-1.70ct

weak absorption band at 460 nm, a 475/480 nm doublet, and a band at 670 nm

inert to weak red

weak to moderate red

Gems & Gemology 2005 fall, p268-269

Corundum - Sapphire

1,76

1,769

0,008

0,009

4,02

4,05

bicoloured: pink and blue

Tunduru, Tanzania

0.64 and 1.97 ct

1,760

1,760

1,768

1,769

Cr

inert

moderate-to-strong orange

Gems & Gemology 1999 Winter, p215

Corundum - Sapphire

1,76

1,768

0,008

0,008

3,99

3,99

purplish pink

Palmer Canyon, Laramie Mts, Wyoming

1.15 ct

chromium lines and a 470 nm doublet

very weak red

moderate orangy red

Gems & Gemology 2001 Winter, p337

Corundum - Sapphire

1,76

1,769

0,008

0,009

4

4

purplish pink to orangy pink

Tamil Nadu, Inia

weak absorption band at 460 nm, a 475/480 nm doublet, and a band at 670 nm

inert to weak red

weak to moderate red

Gems & Gemology 2005 Fall, p268

Corundum - Sapphire

1,76

1,772

0,008

0,008

3,96

4,01

greenish to violetish blue

Bawmar Mine, Mogok, Myanmar

0.20 to 1.63ct

1,760

1,764

1,768

1,772

inert

inert

Gems & Gemology 2013 Winter, p223-232

Corundum - Sapphire

1,76

1,77

0,01

0,01

3,95

4,05

bronze metallic sheen (body colour : blue, green or yellow)

eastern Kenya

Gold Sheen sapphire, 105 stones from 1 to 30ct, sheen effect originates from reflection of light from exsolved hematite-ilmenite

absorption at 450nm

inert

inert

The Journal of Gemmology 2015 Vol 38, No 8, p678-691

Corundum - Sapphire

1,76

1,77

0,01

0,01

4

4,02

green

0.89ct to 5.90ct, lead glass filled;Growth tubes, ‘fingerprints’, lamellar twinning, orange and blue flash effects along filled fissures, green colour concentrations in filled fissures and cavities, flattened gas bubbles trapped in the  glass filler

Inert

Inert to weak orange

The Journal of Gemmology 2015 Vol 34, No.5, p420-427

Corundum - Sapphire

1,76

3,87

3,87

light pink

2.77ct, semi-transparent cabochon,  Filled with Bismuth-Based Glass

weak red

medium red

Gems & Gemology 2017 Spring, p94

Corundum - Sapphire

1,76

1,768

0,008

0,008

4

4

purple

Sri Lanka

9.16ct

line at 693nm (doublet)

inert

moderate red

GIA Gem Database  33079

Corundum - Sapphire

1,76

1,768

0,008

0,008

3,98

3,98

pink

Mogok, Myanmar

2.97ct

doublet at 693nm

weak red

moderate orangy red

GIA Gem Database  34572

Corundum - Sapphire

1,76

1,77

0,008

0,009

3,98

4,01

Aappaluttoq deposit, Greenland

1,760

1,762

1,769

1,770

none to weak red

weak to moderate red

The Journal of Gemmology 2016 35 (4), p 294-306

Corundum - Sapphire

1,76

1,77

0,008

0,009

3,81

4,04

blue

Mogok, Myanmar

inert (80%), weak red (10%)

Gems & Gemology 2021 winter, p292-317

Corundum - Sapphire

1,761

1,77

0,009

0,009

4,03

4,03

blue

Maydan Shahr, Afghanistan

450, 460, 470

inert

inert

Gems & Gemology 2004 winter p343

Corundum - Sapphire

1,761

1,773

0,008

0,008

3,99

4,02

Homogeneous colouration is rare. More common is distinct colour zoning with blue-violet, greenish blue to greenish yellow and yellow domains; star sapphires: grey to blue

Ambondromifehy, Antsiranana Province, Madagascar

geology: magmatic (alkali basalts)

1,761

1,765

1,769

1,773

inert

inert

Gems & Gemology 2000 Fall p 216-233

Corundum - Sapphire

1,761

1,774

0,008

0,009

3,97

4,02

blue, green,yellow, rare: orange to pink to mauve; black star

Inverell (New South Wales) and Anakie  (Queensland), Australia

secondary deposits derived from weathered alkali basalts

1,761

1,765

1,769

1,774

weak to strong Fe spectrum (generally strong)

generally inert

generally inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,761

1,771

0,009

0,009

3,99

4,02

purplish blue to blue-grey

Penglai mine, Hainan Island, China

bands at 450 , 460nm and 470nm

inert

inert

Gems & Gemology 1988 Fall p155-160

Corundum - Sapphire

1,761

1,774

0,008

0,009

3,97

4,02

light blue, dark blue, green, yellow, gold

Australia

1,761

1,765

1,769

1,774

Fe lines

inert

inert

Gems & Gemology 1985 fall p130-146

Corundum - Sapphire

1,761

1,769

0,008

0,008

3,98

4,02

padparadschah, pinkish-orange to pinkish-yellow

Sri Lanka

weak yellowish pink

strong pinkish orange

The Journal of Gemmology 1985 Vol 19, No 5 p389-403

Corundum - Sapphire

1,761

1,77

0,008

0,009

3,99

4,02

purplish pink to purplish red

Pamir Mts, Tajikistan

0.3 to 1.48ct, transparent

1,761

1,762

1,770

1,770

cut-off 450, lines : 468, 475, 476, broad band 530-580, lines 659, 692, 694

very weak to medium : red

strong to very strong : slightly orangy-red to red

The Journal of Gemmology 1998 Vol26, N°2, p103-109

Corundum - Sapphire

1,761

1,771

0,008

0,008

3,91

3,98

blue

Andranondambo, Madagascar

1,761

1,763

1,769

1,771

450nm band

inert to weak greenish blue

inert

The Journal of Gemmology 1996 Vol 25, N°3, p177-184

Corundum - Sapphire

1,761

1,771

0,009

0,009

3,998

4,005

dark blue

Cyangugu district, Rwanda

basaltic type

1,761

1,762

1,770

1,771

375, 390, 450nm

inert

inert

The Journal of Gemmology 1996 Vol 25, N°2, p90-106

Corundum - Sapphire

1,761

1,77

0,008

0,009

3,95

3,97

light blue

Wellawaya, Sri Lanka

1,761

1,762

1,769

1,770

inert

inert

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2008 57/1-2, p28-29

Corundum - Sapphire

1,761

1,77

0,008

0,008

3,99

4

pink, pink+blue

Neelum Valley

1,761

1,762

1,769

1,770

Cr + Fe

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2005 Sep, p111-114

Corundum - Sapphire

1,761

1,771

0,008

0,008

3,91

3,98

pale to dark blue

Bekily, Toliara Province, Madagascar

0.49 - 1.32 ct

1,761

1,763

1,769

1,771

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1995 Mar, p3

Corundum - Sapphire

1,761

1,771

0,008

0,008

3,91

3,98

blue

Andranondambo, Madagascar

1,761

1,763

1,769

1,771

bands at 570nm and 450nm

inert, rarely weak greenish-blue or weak orange

inert

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1996 Mar, p13-22

Corundum - Sapphire

1,761

1,769

0,008

0,008

4

4

blue

Bo Ploi, Kanschanaburi, Thailand

absorption lines around 450-460nm

inert

inert

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1991 Dez, p165-180

Corundum - Sapphire

1,761

1,769

0,008

0,008

4

4

blue

Kanchanaburi, Thailand

450nm, 460nm

inert

inert

The Journal of Gemmology 1984 Vol 19, N°3, p228-239

Corundum - Sapphire

1,761

1,772

0,008

0,009

3,91

4,02

colourless, orange, grey, pink, light to dark blue

Tan Huong-Truc Lau, Yen Bai, Vietnam

1,769

1,772

1,761

1,763

grey/colourl: orange; blue: light blue/orange; orange: orange-red

grey/colourl: orange; blue: light blue/orange; orange: strong orange-red

Gems & Gemology 2012 Fall, p162

Corundum - Sapphire

1,761

1,771

0,008

0,009

4

4,03

pink-brown through brownish pink and purple (incandescent light), yellowish
brown, greyish violet, and greyish greenish blue (fluorescent light)

Tanzania

1.06-2.16 ct

1,761

1,762

1,770

1,771

absorption features typical of ruby and lines at about 450, 460, and 470 nm.

inert

inert

Gems & Gemology 1995 Spring, p64-65

Corundum - Sapphire

1,761

1,769

0,008

0,008

4

4

red-purple

Sri Lanka

8.70ct

band at 530-560nm, lines at 468, 476, 693nm (doublet)

weak red

strong red

GIA Gem Database  33063

Corundum - Sapphire

1,761

1,769

0,008

0,008

3,99

3,99

blue

Bo Phloi, Thailand

2.72ct

lines at 450nm

inert

inert

GIA Gem Database  35095

Corundum - Sapphire

1,761

1,769

0,008

0,008

3,99

3,99

blue

Pailin, Cambodia

1.92ct

line at 450nm

inert

inert

GIA Gem Database  35103

Corundum - Sapphire

1,761

1,769

0,008

0,008

4

4

orangy yellow

Mogok, Myanmar

3.46ct

lines at 450, 468, 476nm

inert

inert

GIA Gem Database  33081

Corundum - Sapphire

1,761

1,769

0,008

0,008

4

4

light blue

Mogok, Myanmar

4.38ct

line at 450nm

inert

inert

GIA Gem Database  33085

Corundum - Sapphire

1,761

1,769

0,008

0,008

3,99

3,99

medium violetish blue

Mogok, Myanmar

8.29ct

line at 450nm

inert

inert

GIA Gem Database  34580

Corundum - Sapphire

1,761

1,769

0,008

0,008

3,99

3,99

brownish orange

Sri Lanka

6.36ct

doublet at 693nm

weak orange

strong orange

GIA Gem Database  33075

Corundum - Sapphire

1,761

1,769

0,008

0,008

3,99

3,99

intense purplish pink

3.93ct

weak red

medium red

Gems & Gemology 2020 Winter, p522

Corundum - Sapphire

1,762

1,771

0,009

0,009

dark blue, nearly opaque in overhead light, translucent and transparent in transmitted light; areas of blue and bluish green

Penglai, Hainan Island, China

very straong bands at 450 and 460 that nearly merge, and narrower band at 470nm

inert

inert

Gems & Gemology 1988 Fall, p155-160

Corundum - Sapphire

1,762

1,77

0,008

0,008

3,99

4,02

blue, green (with brownish cast), yellow, pink, red; many stones have yellowish cores, many stones show a colour shift from blue to violet

Mercaderes, Colombia

weak Fe spectrum

inert

weak to moderate orange to red

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,762

1,77

0,008

0,008

4,03

4,03

near colourless to deep blue (almost black), rarely pink to purple, rarely six-rayed stars

Kashmir (India)

1,762

1,762

1,770

1,770

weak to moderate Fe spectrum

generally inert

generally inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,762

1,772

0,008

0,008

near colourless to deep blue and medium yellow

Bo Ploi, Thailand

weathered alkali basalts

1,762

1,764

1,770

1,772

medium to strong Fe (always present)

inert, occasionally weak chalky blue-green

inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,762

1,77

0,008

0,008

3,99

4,02

blue, green are most common, yellow, pink, red  in lesser quantities

Mercaderes-io mayo area, Cauca, Colombia

inert

inert and weak to moderate orange to red

Gems & Gemology 1985 spring p20-25

Corundum - Sapphire

1,762

1,77

0,008

0,008

3,98

3,99

pink, violet-red, violet, lilac, blue-lilac, bicoloured yellow/blue and yellow/violet

Municipio de Mahuacu, Sacramento, Minas Gerais, Brazil

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2000 Sep, p173-174

Corundum - Sapphire

1,762

1,771

0,008

0,008

3,97

4

blue, yellow, bicoloured blue and yellow

Ambondromifehy, Antsiranana Province, Madagascar

1,762

1,763

1,770

1,771

blue : bands 450, 387, 377nm

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1997 Sep, p123-124

Corundum - Sapphire

1,762

1,77

0,008

0,008

3,97

3,99

blue

Malawi

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1990 Apr, p89-92

Corundum - Sapphire

1,762

1,775

0,008

0,01

3,95

4,05

blue

Loch Roag, Isle of Lewis, Scotland

1,762

1,767

1,772

1,775

diffuse braod band at 450nm

inert

inert

The Journal of Gemmology 1984 Vol XIX, N°4, p336-342

Corundum - Sapphire

1,762

1,774

0,008

0,009

3,93

3,99

pink, brownish-red, red

Ngoronghoro, Morogoro Region,Tanzania

1,762

1,765

1,770

1,774

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1989 Apr, p44-46

Corundum - Sapphire

1,762

1,775

0,007

0,01

3,96

4,05

purple, purplish red

Marosely, Madagascar

1,769

1,775

1,762

1,767

Cr³+

inert to weak: red

inert to strong: red

The Journal of Gemmology 2009 Vol 31/N°5-8, p171-179

Corundum - Sapphire

1,762

1,77

0,008

0,008

3,92

4,17

blue

cobalt-doped glass-filled; Strong red to orange-red with chelsea filter, red colour concentrated in the fissures

lines at 450, 460, 471 nm; Co-glass spectrum from the glass

inert to weak red

inert to weak red

http://www.ruby-sapphire.com/glass-filled-sapphire.htm 2013

Corundum - Sapphire

1,762

1,77

0,008

0,008

40

4,01

dark blue

star sapphire, semi-transparent to semi-translucent

bands at 450, 460, and 470 nm

inert

inert

Gems & Gemology 1998 Summer, p140-141

Corundum - Sapphire

1,762

1,77

blue

Kashmir, India

6.70 ct

line at 450 nm (Fe) and in the red (Cr

inert

inert

Gems & Gemology 1983 Summer, p74

Corundum - Sapphire

1,762

1,77

0,008

0,008

4,03

4,03

orangy yellow

filled with lead glass, 4.27 ct

absorption band at around 450nm

reddish orange

reddish orange

Gems & Gemology 2014 Spring, p92-93

Corundum - Sapphire

1,762

1,772

0,008

0,009

3,98

4,01

yellow+blue+green+brown, "gold sheen"

gold sheen sapphire, 14 sapphires up to 97.69ct

inert

inert

Gems & Gemology 2016 Winter, p413-414

Corundum - Sapphire

1,762

1,77

0,008

0,008

4

4

purple

Montana

10.47ct

inert

inert

Gems & Gemology 2020 Summer p286

Corundum - Sapphire

1,763

1,775

0,008

0,008

3,99

4,03

Madagascar

1,763

1,767

1,771

1,775

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1996 Dec, p155

Corundum - Sapphire

1,763

1,773

0,008

0,008

3,97

3,98

orange (padparadscha)

Malawi

1,763

1,765

1,771

1,773

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1989 Dec, p164-165

Corundum - Sapphire

1,763

1,773

0,008

0,008

3,99

4,06

reddish brown

Umba Valley, Tanzania

0.88 to 7.8 ct

1,763

1,765

1,771

1,773

450nm line, 693nm doublet

The Journal of Gemmology 1984 Vol 19, N°2, p139-144

Corundum - Sapphire

1,763

1,774

0,008

0,01

 greenish yellow

Ploi Waen area of Chanthaburi, Thailand

1,763

1,765

1,772

1,774

Gems & Gemology 2016 Fall, p 325-326

Corundum - Sapphire

1,763

1,772

0,009

0,009

4,01

4,01

orangy yellow

Chanthaburi, Thailand

3.89ct

band at 450-470nm, line at 477nm

inert

inert

GIA Gem Database  35147

Corundum - Sapphire

1,764

1,778

0,008

0,008

medium yellow to greenish yellow to deep yellow-orange, golden-star

Chantaburi (Thailand)

weathered alkali basalts

1,764

1,770

1,772

1,778

strong Fe spectrum

inert, occasionaly weak red

inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,764

1,778

0,008

0,008

green to blue, (Chantaburi generally dark and inky; Phrae generally dark but slightly violet), black stars

Chantaburi  & Phrae (Thailand)

weathered alkali basalts

1,764

1,770

1,772

1,778

always strong Fe spectrum

inert

inert

Ruby & Sapphire, R. Hughes, 1997 

Corundum - Sapphire

1,764

1,772

0,008

0,008

3,98

3,98

blue

China

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1997 Jun, p64

Corundum - Sapphire

1,764

1,773

0,009

0,009

3,97

3,97

Lodwar, Lake Turkana, Kenya

Zeitschrift der Deutschen Gemmologischen Gesellschaft 1989 Aug, p89-94

Corundum - Sapphire

1,764

1,772

0,008

0,008

3,98

4,03

dark blue to very dark blue

Maydan Sahr, Afghanistan

0.40 and 0.72 ct

450, 460, and 470 nm bands

inert

inert

Gems & Gemology 2002 Summer, p181

Corundum - Sapphire

1,764

1,775

0,008

0,01

yellow

Anakie area in Queensland, Australia

1,764

1,766

1,773

1,775

Gems & Gemology 2016 Fall, p 325-326

Corundum - Sapphire

1,764

1,772

0,008

0,008

4,02

4,02

dark yellowish green

Thailand

5.28ct

lines at 450, 468nm

inert

inert

GIA Gem Database  35128

Corundum - Sapphire

1,765

1,773

0,008

0,008

3,98

4,06

brownish-orange

Tanzania

inert

inert

The Journal of Gemmology 1985 Jan, p390

Corundum - Sapphire

1,765

1,775

0,01

0,01

3,95

4,03

yellow to brownish green to blue

Yabelo, Ethiopia

bands at 450, 460, 470nm

inert

inert

Gems & Gemology 2011 Fall, p247

Corundum - Sapphire

1,768

1,777

0,009

0,009

3,98

4,05

yellow-brown, reddish orange

Kalalani, Tanzania

450nm

none

none

Gems & Gemology 1999 summer p116

Corundum - Sapphire

1,78

1,788

0,008

0,008

pink

0.95ct, Cr-diffused

Cr

weak red  with chalky blue-white patches

strong red

The Journal of Gemmology 2015 Vol 34, No.6, p486-488

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

ne min

ne max

no min

no max

Reference

Corundum

1.757

1.779

0.008

0.009

3.99

4.1

http://www.gemmology.be 

corundum

1.757

1.779

0.007

0.009

3.8

4.06

1.757

1.770

1.765

1.779

http://www.geminterest.com 

Corundum - Sapphire

1.757

1.774

0.008

0.009

3.99

4.01

1.757