4.31 Ct. Blue Sapphire from Thailand

This oval shape blue sapphire weighs 4.31 carat and measures 10.24 x 9.11 x 5.32 mm, dimensions that provide a substantial face up presence while maintaining a balanced profile for ring settings. The gem is transparent and has been fashioned with a mixed brilliant cut, a choice that merges pavilion facets to encourage return of light with a crown arrangement that maintains a classic sapphire silhouette. Clarity is graded as very very slightly included, evaluated at eye level, indicating the stone is effectively eye clean with only minor characteristics visible under magnification. Color intensity is described as dark, producing a deep and saturated blue that reads as rich and contemplative in a variety of lighting conditions. The polish is excellent, and the stone has been heat treated, a common and stable enhancement, with origin recorded as Thailand. The Natural Sapphire Company presents this piece with full disclosure of its treatments and origin, aligning with industry standards for transparency.

Optical behavior of this sapphire is determined by its combination of cut, color, and clarity. The mixed brilliant cut contributes to a controlled scintillation pattern, offering flashes of light from the crown facets while preserving depth of color from the pavilion. At the stated dimensions the table and crown proportions are conducive to an engaging face up appearance, where the dark color intensity produces a velvety blue that can appear nearly inky under subdued light, and reveal more nuanced blue tones under stronger, cool white illumination. The very very slightly included clarity grade means that inclusions do not distract from the overall visual appeal at normal viewing distance, and the excellent polish supports crisp facet junctions which aid in delivering clean reflections. These combined attributes make the gem visually cohesive, and suitable for use as a primary center stone in an engagement setting where depth of color is a defining characteristic.

Durability and permanence are key considerations for a stone intended for daily wear, and sapphire is among the hardest natural gem materials available, ranking nine on the Mohs scale. This inherent toughness makes the sapphire resistant to scratches, abrasion, and general wear that occur with consistent use. The heat treatment applied to this stone is stable and widely accepted within the trade, serving to enhance color uniformity and clarity without compromising structural integrity. With an excellent polish and sound cutting, the stone presents clean facets and edge definition that will retain its finish with normal care. The origin of Thailand is noted for producing sapphires with deep tones, and provenance is provided to inform choice and valuation. The Natural Sapphire Company can provide additional documentation upon request to support the gem description and the stated enhancements.

As an engagement center stone, this 4.31 carat oval sapphire is well suited to a variety of classic and contemporary settings. The oval outline offers elongation on the finger, often creating a flattering visual effect, while the size and depth support setting styles that emphasize the stone without overwhelming it. A solitaire mounting in a four or six prong arrangement will present the gem cleanly, allowing the dark blue field to be the focal point, whereas a halo of smaller accent stones will increase perceived diameter and introduce additional brilliance to counterbalance the darker body color. Protective designs such as a full or partial bezel will offer added security for active wearers, and metal choice will influence the perceived warmth and contrast of the blue. Yellow or rose gold will introduce a warming contrast that can soften the depth, while white gold or platinum will create a crisp, contemporary frame. Practical considerations such as finger size, lifestyle, and preference for sparkle versus color depth will guide the final design.

This sapphire combines measurable specifications with aesthetic and practical attributes that make it an apt choice for an engagement ring that favors depth of color and enduring wearability. The 4.31 carat weight and 10.24 x 9.11 x 5.32 mm dimensions lend presence without excessive bulk, the mixed brilliant cut and excellent polish support attractive light performance, and the very very slightly included clarity provides an essentially eye clean appearance. Heat treatment is disclosed and consistent with standard gem treatment practices, and the Thai origin contributes to the stone character. For clients seeking a center stone with a classic silhouette and a rich, dark blue personality, this sapphire represents a considered option. The Natural Sapphire Company is available to provide further technical details, high resolution imagery, and guidance on complementary settings to ensure that the chosen mounting aligns with intended wear and aesthetic priorities.