Bangkok Neelam Stone 7.18 Ratti (6.53 Carat) - Blue Sapphire

Bangkok Blue Sapphire (Neelam) – 6.53 Carat (7.18 Ratti) Oval Mix Cut

This Bangkok Blue Sapphire (Neelam) weighs exactly 6.53 Carats (7.18 Ratti) with calibrated dimensions of 12 x 8.5 x 6 mm. Expertly faceted into a balanced Oval Mix Cut, this gemstone displays a deep, commanding blue hue, vitreous corundum luster, and balanced proportions ideal for fine jewelry mounting. It has been heated and glass-filled; the treatment and the care it needs are explained below.

Mineralogical Identity & Physical Constants: Blue Sapphire is the precious blue variety of corundum (aluminum oxide, Al₂O₃), colored by intervalence charge transfer between trace titanium (Ti⁴⁺) and iron (Fe²⁺) substituting within the crystal lattice. Corundum ranks 9 on the Mohs scale (second only to diamond), but the glass that fills this stone's fissures is much softer, so it needs gentle care. Corundum has a refractive index of 1.762 to 1.770 (birefringence 0.008, uniaxial negative), a specific gravity of 3.99 to 4.01, and a diagnostic trigonal crystal system.

Bangkok & Treatment: In the Indian gem trade, Bangkok is the name for corundum of this kind, after the Thai gem-trading center where much of the world's corundum is treated and traded; it describes how the stone was processed, not where it was mined. This sapphire has been heated and glass-filled: heating improves the color, and glass fills fine fissures that reach the surface so that they show less. This is why a Bangkok Blue Sapphire shows a rich color at a fraction of the price of an untreated stone.

Cultural Legacy & Traditional Wearing: Known in Sanskrit as Neelam (नीलम) or Indraneel, Blue Sapphire holds a prominent position in Vedic astrology as the primary gemstone linked to Saturn (Shani). Traditionally, it is mounted in Sterling Silver (925 Silver), White Gold, or Panchdhatu for rings and pendants worn on the middle finger of the working hand on Saturday mornings during Shukla Paksha.

Please Note: Ratna Gems shares these historical, cultural, and gemological details solely for educational awareness. We sell all gemstones strictly on the basis of verified physical authenticity, mineral quality, and independent laboratory certification, and make no astrological, metaphysical, or curative claims.

Care Instructions

• Wipe gently with a soft, damp cloth, then dry it with a lint-free microfiber cloth.
• Store it separately from diamonds and other gemstones, and take it off before sport, heavy work or household cleaning.
• Special Care Note for Glass-Filled Stone: Strictly avoid ultrasonic cleaners, steam machines, household acids (including lemon juice and vinegar), bleaches and detergents. Before any setting, resizing or repair, tell your jeweler it is glass-filled and keep it away from the torch, as heat and chemicals can damage the filler.

Frequently Asked Questions