Star Sapphire Triple Star 2.62 Cts 19747 Natural Ceylon Loose Gem
STAR SAPPHIRE TRIPLE STAR 2.62 Cts 19747 Extremely Rare Gem. 7.8 x 6.8 mm. 100% Natural - Not treated in any way. Rare Collectors Gem Suitable for Museums, Institutions and Students of Gemology. Beautiful Center-stone for an engagement Ring.
Ployasterism - Rare Multiple Starts displayed in Star Sapphires Refractive Index: 1.759-1.778 Hardness: 9 Chemical Comp: AL2O3 Density: 4.00 Crystal Group: Hexagonal 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 TRIPLE STAR 2.62 Cts 19747 NATURAL CEYLON LOOSE GEM" is in sale since Thursday, May 9, 2019. This item is in the category "Jewelry & Watches\Loose Diamonds & Gemstones\Loose Gemstones\Sapphire\Natural Sapphires". The seller is "cresla" and is located in Colombo. This item can be shipped worldwide.
- Shape: Oval
- Country of Origin: Sri Lanka
- Country/Region of Manufacture: Sri Lanka
- Natural/Lab-Created: Natural
- Length: 7.8 mm
- Width: 6.8 mm
- Cut Grade: Good
- Variety/Type: White
- Color: White
- Transparency: Translucent
- Treatment: None (No Enhancement)
- Brand: Cresla
- Total Carat Weight (TCW): 2.62