6.13 Ct. Blue Sapphire from Ceylon (Sri Lanka)

This specimen is a transparent, radiant shape blue sapphire weighing 6.13 carats, with precise dimensions of 11.05 by 8.60 by 7.14 millimeters, offered by The Natural Sapphire Company. The stone exhibits vivid color intensity, a clarity grading of very slightly included as evaluated at eye level, and an excellent polish. The cut is a radiant style, incorporating a mixed facet architecture that marries brilliant crown facets with a more structured pavilion, and the stone has been heat treated, a widely accepted enhancement for corundum which stabilizes and intensifies the blue hue. Origin is Ceylon, Sri Lanka, a source known for producing sapphires with a lively chroma and a characteristic interplay between blue saturation and lightness, and the overall presentation is one of open transparency coupled with saturated color, a combination that is uncommon in material of this size.

From a lapidary perspective the radiant cut on this 6.13 carat example has been executed to balance weight retention with optimal light performance. The mixed facet design, with truncated corners and a pavilion organized to return color rather than disperse it as fire, produces large flashes of scintillation across the table and step like flashes along the girdle, which is desirable for a deeply colored corundum. With a depth of 7.14 millimeters relative to the average of the length and width, this sapphire has an approximate depth percentage of 72.7 percent, a proportion that contributes to the stone s perceived color saturation by increasing the optical path length through the body of the gem. Corundum has a specific gravity close to 4.00, a density that means a 6.13 carat sapphire such as this will present with substantial visual mass at the stated dimensions, and the cutter has preserved that mass while achieving consistent facet junctions and a finely applied polish that maximizes both brilliance and color uniformity across the table and pavilion facets.

The carat weight is central to the value proposition of this sapphire, because in corundum weight correlates strongly with both rarity and per carat price escalation. Large, transparent sapphires from Ceylon that combine vivid color, eye clean clarity, and excellent cutting are significantly rarer than smaller stones of similar quality, due to the geological conditions required for crystal growth that yield homogenous color and minimal inclusions at larger sizes. As carat weight rises, the probability of disruptive inclusions or zoning increases, which forces cutters to make difficult trade offs between yield and optical properties. That this specimen maintains a very slightly included clarity at 6.13 carats indicates an exceptional rough crystal and a disciplined cutting strategy aimed at preserving color saturation and symmetry rather than sacrificing mass for a more conventional shallow pavilion. The heat treatment applied is standard and stable, enhancing the blue without obscuring the stone s natural features, and the Ceylon origin confers additional market desirability because collectors and connoisseurs prize the island s characteristic tonal range. From a valuation standpoint the effect of the 6.13 carat weight is nonlinear, in other words the per carat value of this stone will be markedly higher than that of smaller sizes with otherwise equivalent color and clarity, and the resultant rarity premium makes this sapphire suitable for high end bespoke commissions where presence and rarity are primary considerations.

If you require further technical data, such as exact facet counts, metrology images, or comparative light performance analysis, The Natural Sapphire Company can provide additional documentation and high resolution photography. Practical considerations for setting include the stone s rectangular proportions and truncated corners which favor secure bezel or prong settings that protect corners while showcasing the table and pavilion interaction, and the depth profile will influence bezel height and seat design to ensure optimal face up presentation. For clients focused on investment and curatorial quality, the combination of 6.13 carat weight, radiant cutting, vivid Ceylon color, very slightly included clarity at eye level, and excellent polish represents a confluence of attributes that together underpin both immediate aesthetic impact and long term rarity.