Mineral | Corrundum |
---|---|
Chemistry | Al2O3 |
Color | Red - Vivid Red |
Refractive Index | 1.762 - 1.770 |
Birefringence | 0.008 - 0.010 |
Specific Gravity | 4.00 |
Mohs Hardness | 9.0 |
Star rubies are known for their asterism phenomenon, which creates a star-like sheen when the stone is moved in the light. This effect is caused by the reflection of light off tiny rutile inclusions within the gem, forming a six-rayed star pattern.
Mineral | Corrundum |
---|---|
Chemistry | Al2O3 |
Color | Red - Vivid Red |
Refractive Index | 1.762 - 1.770 |
Birefringence | 0.008 - 0.010 |
Specific Gravity | 4.00 |
Mohs Hardness | 9.0 |
Star rubies are among the rarest and most expensive gemstones in the world due to their unique optical phenomenon. Only about 1 percent of all rubies display the six-rayed star effect. Quality and size significantly influence the value of star rubies, with some top specimens selling for millions of dollars.
The most desirable color for star rubies is "pigeon's blood," characterized by its intense raspberry-red to orangey-pinkish red hue.
Star rubies are sourced from various locations, including Africa, Burma (Myanmar), Australia, India, and Sri Lanka. They have a rich history and have been used in royal jewelry and religious rituals.
The asterism in star rubies is caused by rutile needle inclusions, known as "silk," which form intersecting lines to create the star effect. The clarity of the star effect depends on the amount of silk present.
To clean star rubies, use warm water and mild soap to remove dirt and debris. Avoid harsh chemical solutions. Do not use diamond jewelry cleaner on star rubies, as their hardness is slightly lower than that of diamonds (9 vs. 10 on the Mohs scale).