STAR SAPPHIRE 12 RAY 3.43 Cts OVAL DARK GREY NATURAL CEYLON LOOSE GEMSTONE 20462

  
STAR SAPPHIRE 12 RAY 3.43 Cts OVAL DARK GREY - 20462 RARE COLLECTORS GEM. 8.8 x 7.2 mm. 100% Natural - Not treated in any way. Rare Collectors Gem Suitable for Museums, Institutions and Students of Gemology.

Will make a Gorgeous Ring or Pendent accented with Diamonds. Among the Rarest of gemstones.

Refractive Index: 1.759-1.778 Hardness: 9 Chemical Comp: AL2O3 Density: 4.00 Crystal Group: Hexagonal 12 Rayed Star Sapphires display a 12 rayed star - By light reflecting off the silky crystallizations of retile inside called asterism. Star Sapphires belong to the Corundum family and are translucent to opaque. 12 Rayed Stars are extremely rare and are sought-after by collectors.

Polyasterism is the display of more than one star within a narrow angle of observation; they aren't stars of same star-network. Rarely Sri Lankan star sapphire produce display multiple stars or polyasterism. Relatively common two-stars are often called "Siamese twins" and rare three-stars "triplets" in the trade.

They not only comprise 6-ray stars but also 12-ray stars, prevalent among blue star, star ruby, and all other sapphire colors, sometimes fetching higher prices than that of single star stones. Morphological disturbances in the single crystal or forming a compound crystal by bonding/fusing/cementing several crystals together by geological reasons or Branching/penetrating of crystals are the two main causes that convert a star sapphire into a polyasteric stone.

Displacement of two or more sections by glide causes display of asterism independently in the individual sections arising from their rutile needle inclusions - this is the polyasterism in single crystals. Similarly compound crystal formed by aggregation of crystals display the effect. The item "STAR SAPPHIRE 12 RAY 3.43 Cts OVAL DARK GREY NATURAL CEYLON LOOSE GEMSTONE 20462" is in sale since Monday, April 19, 2021. This item is in the category "Jewelry & Watches\Loose Diamonds & Gemstones\Loose Gemstones". The seller is "cresla" and is located in Colombo. This item can be shipped worldwide.

1. Shape: Oval
2. Country of Origin: Sri Lanka
3. Country/Region of Manufacture: Sri Lanka
4. Natural/Lab-Created: Natural
5. Gemstone Type: Sapphire
6. Length: 8.8 mm
7. Width: 7.2 mm
8. Cut Grade: Good
9. Variety/Type: Star Sapphire
10. Color: Dark Grey
11. Gemstone Creation: Natural
12. Transparency: Translucent
13. Treatment: None (No Enhancement)
14. Brand: Cresla
15. Total Carat Weight (TCW): 3.43