GIA Gem Project
Corundum


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Corundums (ruby and sapphires) occur in all colors of the spectrum, and have remained popular gemstones from ancient times to the present day. Photo by Robert Weldon/GIA
Ruby and sapphire (usually blue, but also in every other color) have been the most important colored gemstones for several thousand years. Originating historically in southeast and central Asia, and more recently in eastern Africa, these colored varieties of the mineral corundum have been much sought as gems because of their rarity, color and durability. Gem corundum can display asterism and chatoyancy due to the presence of oriented mineral inclusions, and in some cases, a change of color when viewed under different light sources.

33066

1.77 ct Corundum - Ruby
Myanmar (PDF)
33068

1.62 ct Corundum - Ruby
Nepal (PDF)
33069

2.02 ct Corundum - Ruby
Sri Lanka (PDF)


 
33070

3.05 ct Corundum - Ruby
Sri Lanka (PDF)



 
35115

2.47 ct Corundum - Ruby
Thailand (PDF)


 
35103

1.92 ct Corundum - Sapphire
Cambodia (PDF)



 
34572

2.97 ct Corundum - Sapphire
Myanmar (PDF)


 
33081

3.46 ct Corundum - Sapphire
Myanmar (PDF)



 
33085

4.38 ct Corundum - Sapphire
Myanmar (PDF)



 
34575

5.78 ct Corundum - Sapphire
Myanmar (PDF)



 
33078

6.40 ct Corundum - Sapphire
Myanmar (PDF)


 
35147

3.89 Corundum - Sapphire
Thailand (PDF)



 
35146

3.97 ct Corundum - Sapphire
Thailand (PDF)



 
34581

6.99 ct Corundum - Sapphire
Myanmar (PDF)



 
34580

8.29 ct Corundum - Sapphire
Myanmar (PDF)



 
33092

3.48 ct Corundum - Sapphire
Sri Lanka (PDF)


 
33074

4.51 ct Corundum - Sapphire
Sri Lanka (PDF)



 
33075

6.36 ct Corundum - Sapphire
Sri Lanka (PDF)



 
33061

7.74 ct Corundum - Sapphire
Sri Lanka (PDF)



 
33063

8.70 ct Corundum - Sapphire
Sri Lanka (PDF)


 
33079

9.16 ct Corundum - Sapphire
Sri Lanka (PDF)



 
35144

4.94 ct Corundum - Sapphire
Thailand (PDF)



 
35128

5.28 ct Corundum - Sapphire
Thailand (PDF)



 
33084

15.87 ct Corundum - Sapphire
Sri Lanka (PDF)



 
33087

4.29 ct Corundum - Sapphire
Tanzania (PDF)



 
33077

5.06 ct Corundum - Sapphire
Tanzania (PDF)



 
35138

2.20 ct Corundum - Sapphire
Thailand (PDF)


 
35095

2.72 ct Corundum - Sapphire
Thailand (PDF)



 
35111

2.72 ct Corundum - Sapphire
Thailand (PDF)



 
33080

2.86 ct Corundum - Sapphire
Thailand (PDF)



 
35112

3.01 ct Corundum - Sapphire
Thailand (PDF)



 
35113

3.39 ct Corundum - Sapphire
Thailand (PDF)



 
35110

3.76 ct Corundum - Sapphire
Thailand (PDF)



 
33091

7.65 ct Corundum - Sapphire
Thailand (PDF)