1.69 Ct. Grey Star Sapphire from Ceylon (Sri Lanka)

This translucent, fancy shape grey star sapphire weighs 1.69 carats, and measures 10.94 x 5.16 x 2.89 mm, presenting a carefully proportioned cabochon profile that optimizes the asterism characteristic of high quality star sapphires, The Natural Sapphire Company sources and presents this piece as an unenhanced, natural gem of Ceylon origin, Sri Lanka. The cutting style is a classic domed cabochon, executed to a profile height that balances star visibility with overall body tone. The gem is graded as very very slightly included evaluated at eye level, indicating only minimal needle or pinpoint inclusions visible without magnification, and it displays medium color intensity in the grey range. The polish is excellent, producing a smooth, reflective surface that allows the asterism to resolve clearly against the translucent body color. No enhancement has been performed, so the stone exhibits its natural interplay of color, translucency, and internal structure, preserving both its material and market integrity.

Technically, the asterism in this cabochon is produced by a dense, oriented network of rutile needles aligned along the trigonal symmetry of corundum, producing an orthodox six ray star when light is properly oriented. The cutting technique for a high quality star sapphire requires systematic orientation of the crystal blank so that the dome axis is perpendicular to the dominant rutile orientation, ensuring the star is centered when viewed face up. The cabochon height, measured here at 2.89 mm, is sufficient to allow light to interact across multiple layers of rutile inclusions, which sharpens the star without sacrificing too much transparency. The fancy shape requires additional skill in determining the axis of the dome, because non circular outlines can bias the optical path, but in this specimen the cutter achieved uniform ray symmetry, which is evident in even star contrast across the face. The medium color intensity in grey provides a neutral background that contrasts well with the white asterism, while the very very slightly included clarity contributes to star definition, since excessive translucency with no inclusions would diffuse the star, and heavy inclusions would obscure it. The excellent polish is critical, because microabrasions or polishing lines scatter light and soften the star, whereas a high gloss finish concentrates reflected light into crisp rays.

On the Mohs scale the material in this star sapphire is corundum, which rates at 9, making it one of the hardest and most durable gem materials available for jewelry use. For context, diamond is harder at 10, but common jewelry minerals such as topaz at 8 and quartz at 7 are appreciably softer, so a corundum sapphire offers superior scratch resistance compared to most colored gemstones. Hardness at 9 means daily wear as a ring stone is feasible, subject to appropriate setting and handling. Toughness, which describes resistance to fracture, is generally good for corundum, because it lacks perfect cleavage, but rutile inclusions can act as fracture initiation points under extreme impact, so practical durability considerations recommend settings that mitigate side strikes. A robust bezel or protective halo setting will preserve the domed face and minimize lateral impact, while secure prongs can be used if the gallery is engineered to shield the girdle. Cleaning may be performed with warm water, mild detergent, and a soft brush, ultrasonic and steam cleaners are typically safe for unenhanced corundum but caution is advised if the mounting includes other materials, and sudden thermal shock or harsh acid baths should be avoided to prevent matrix or filler damage in mixed material settings.

This grey star sapphire from Ceylon combines natural asterism, unenhanced origin, and meticulous cutting, making it a technically interesting and durable choice for connoisseurs and setters who value precise optical performance. The balance of dome height, cabochon symmetry, translucent body, medium color intensity, and very very slightly included clarity evaluated at eye level produces a star that is well defined and stable across viewing angles, suitable for custom settings where both the optical effect and long term resilience matter. For professional buyers seeking full technical documentation or imagery, The Natural Sapphire Company can provide detailed dossiers on orientation, cut parameters, and handling recommendations to assist in mounting and retail presentation.